Surface finish plays a critical role in how CNC machined parts look, perform, and last. However, surface finish charts, roughness symbols, and Ra values often create confusion instead of clarity.
Last Updated on April 28, 2026 by DZ Making Team
In real CNC projects, surface finish becomes a hidden risk. Over-specifying surface finish increases machining time, cost, and rejection rates. Under-specifying it leads to friction issues, premature wear, sealing failures, or poor coating adhesion. These problems usually surface late in assembly or during product use, when corrections are expensive and disruptive.
That’s why roughness measurement on critical surfaces, and in some high-precision projects on each individual component, can help reduce cost and avoid late-stage surprises. A proactive surface finish plan allows manufacturers to verify functional surfaces more clearly, instead of relying only on generic standards. This guide explains surface finish charts, roughness parameters, engineering symbols, and finish selection from a practical CNC manufacturing perspective.
What Is Surface Finish?
Surface finish describes the texture and condition of a part’s surface after machining or post-processing. It defines how smooth or rough the surface is at a microscopic level and directly influences friction, wear, sealing, coating adhesion, and visual quality. In CNC machining, surface finish is a functional specification, not just an aesthetic detail.
Surface finish focuses on surface texture, not dimensions or tolerances. Two parts with identical sizes can perform very differently if their surface finishes differ. This is why surface finish is clearly defined on engineering drawings and often verified during inspection. In practice, surface finish can be achieved directly through machining or by applying additional finishing processes.
Common surface finish types in CNC machining include:
- As-machined finish: Direct result of CNC milling or turning, with visible tool marks
- Polished finish: Smoothed surface for reduced roughness and improved appearance
- Ground finish: High-precision finish with tight roughness control
- Bead blasted finish: Uniform matte surface with reduced visual tool marks
- Brushed finish: Directional texture for aesthetic or functional purposes
- Anodized finish: Aluminum surface treatment that improves corrosion resistance and appearance
- Plated finish: Metal coating such as nickel or chrome for protection or conductivity
- Powder-coated finish: Durable protective coating with consistent surface appearance
Why Surface Finish Is Critical in CNC Machining?
Surface finish directly shapes how a machined part performs in real-world conditions. It influences contact behavior, durability, sealing reliability, and downstream processes. Ignoring surface finish often leads to higher cost, rework, or early failure, even when dimensions meet tolerance.
Surface Roughness Measurement for Functional Performance
Surface finish and roughness solutions help manufacturers control surface quality with measurable data instead of visual judgment. Contact profilometers, scanning probes, and optical measurement systems can check microscopic surface texture and confirm whether critical areas meet the required Ra value or other roughness parameters.
This is especially important for bearing surfaces, sealing faces, sliding parts, medical components, aerospace parts, and other precision applications. By measuring roughness during inspection or process validation, CNC manufacturers can detect surface problems early, reduce rework, and ensure the part meets its functional requirements, not just its appearance requirements.
Improves Aesthetic Appeal
Surface finish defines how a part looks and feels at first contact. Different textures create different impressions, from refined and precise to rugged and functional. Surface treatments such as anodizing, plating, or painting interact with surface texture to control color and reflectivity. Consistent finishes across features and components significantly improve perceived product quality.
Reduces Friction
Surface finish influences how smoothly two surfaces move against each other. Rough textures create more contact points and higher resistance during motion. A controlled, smoother surface reduces mechanical interference at the interface, allowing parts to slide more consistently. This improves motion stability and lowers heat generation, especially in applications with limited or intermittent lubrication.
Enhances Wear Resistance
Surface finish affects how a surface holds up under repeated contact and load. Rough surfaces contain sharp peaks that wear down quickly and accelerate material loss. A smoother, controlled finish distributes contact stress more evenly across the surface. This slows abrasive wear, reduces surface damage over time, and helps extend the service life of machined components.
Improves Coating Adhesion
Surface finish influences how coatings interact with the base material. Surface texture affects mechanical bonding and chemical attachment during processes such as anodizing, plating, or painting. Excessively flat surfaces can weaken adhesion, while overly rough textures disrupt coating uniformity. An appropriate surface profile helps coatings bond evenly and maintain long-term durability.
Improves Sealing Performance
Surface finish plays a critical role in how sealing interfaces perform under pressure. Irregular surface textures can create micro-channels that allow fluid or gas leakage. At the same time, overly flat surfaces may reduce seal grip and stability. A well-defined surface texture supports consistent contact, helping seals deform properly and maintain reliable sealing over time.
What Are the Key Properties of Surface Finish?
Surface finish is defined by several measurable properties that describe how a surface behaves at a microscopic level. These properties explain why two surfaces with the same Ra value can perform differently in real applications. Understanding them helps interpret surface finish charts and engineering drawings more accurately.
Surface Roughness
Surface roughness describes the fine, closely spaced irregularities left on a surface after machining or finishing. It represents short-wavelength variations caused by cutting tools, feed rates, and material removal mechanisms.
Roughness directly influences friction, wear, sealing, and coating performance. Parameters such as Ra, Rz, and Rt are commonly used to quantify roughness and appear most often on CNC drawings and inspection reports.
Waviness
Waviness refers to surface variations with longer spacing than roughness, representing broader undulations rather than fine tool marks. These features usually result from machine vibration, tool deflection, thermal distortion, or unstable cutting conditions.
Waviness is commonly evaluated using parameters such as Wa (waviness average) and Wt (total waviness height). Unlike Ra, waviness parameters focus on longer wavelength surface behavior. Excessive waviness can affect load distribution, bearing performance, and sealing reliability, even when roughness values fall within specification.
Lay
Lay describes the directional pattern of surface texture created during machining or finishing. Common lay patterns include linear, circular, radial, or multidirectional textures. Lay direction matters when surfaces slide against each other or interface with seals. Aligning lay orientation with the direction of motion or sealing pressure can reduce friction, improve sealing effectiveness, and extend component life.
Common Surface Finish Symbols Used in Engineering Drawings
Surface finish symbols provide a standardized way to communicate surface texture requirements on engineering drawings. These symbols allow designers, machinists, and inspectors to reference measurable surface characteristics without lengthy notes. Correct interpretation is essential for achieving functional performance while avoiding unnecessary manufacturing costs.
Ra
Ra represents the average surface roughness of a machined surface. It measures the arithmetic mean of the absolute height deviations of the surface profile from the mean line over a defined sampling length. In practical terms, Ra indicates how rough or smooth a surface is at the microscopic level, rather than how accurate it is dimensionally.
Ra values are usually expressed in micrometers (µm) or microinches (µin) and appear on CNC drawings more often than any other roughness parameter. Because Ra reflects overall roughness, it works well as a general reference. However, Ra averages all surface features equally and may not capture isolated peaks or deep valleys that affect functional performance.
Rz
Rz indicates the average peak-to-valley height of a surface profile and highlights surface irregularities more clearly than Ra. It focuses on the vertical distance between prominent peaks and valleys, which makes it useful for evaluating functional areas where contact pressure, sealing performance, or load distribution matters.
Rz values are expressed in micrometers (µm) or microinches (µin), depending on the standard applied. During measurement, the surface profile is divided into five sampling segments. The maximum peak-to-valley height is measured within each segment, and the average of these values defines the final Rz value.
Rt
Rt refers to the total vertical distance between the highest peak and the lowest valley within the entire evaluation length of a surface profile. It highlights the most extreme surface deviation and is useful when isolated defects, deep scratches, or sharp peaks could affect function or reliability.
Like Ra, Rt uses the same roughness unit system and is derived from the measured surface profile. Instead of averaging deviations, Rt focuses on the single largest peak-to-valley distance observed over the full evaluation length, which makes it useful for identifying worst-case surface conditions.
Rq
Rq reflects the statistical roughness level of a surface by evaluating how surface height deviations vary around the mean line. Compared with Ra, this parameter places greater emphasis on larger peaks and deeper valleys, which makes it more responsive to pronounced surface irregularities.
Rq follows the same unit convention as Ra but applies a root mean square calculation to the measured profile deviations. Because larger deviations carry more weight in this method, Rq increases more rapidly than Ra when extreme surface features are present, which makes it suitable for precision contact and surface-energy-sensitive applications.
Rp
Rp focuses on the highest surface peak above the mean line within the sampling length. Unlike average-based parameters, this value isolates individual surface peaks, which often dominate early wear behavior, scratching risk, and initial contact damage.
During evaluation, the surface profile is scanned and the largest positive deviation from the mean line is identified. Rp is especially relevant for sliding or mating surfaces where raised asperities can concentrate contact stress and accelerate surface degradation during initial operation.
Rv
Rv focuses on the deepest surface valley below the mean line within the sampling length. This parameter highlights recessed surface features rather than peaks or average roughness, which makes it useful when valleys influence functional behavior.
When measuring Rv, attention is placed on the most pronounced downward deviation in the surface profile. Deep valleys can affect sealing performance, fluid retention, corrosion behavior, and coating uniformity, particularly in applications where surface depressions trap media or contaminants over time.
Ry
Ry refers to the largest vertical distance between a surface peak and a valley observed in a single evaluated segment of the surface profile. It highlights localized surface extremes rather than overall roughness trends.
Engineers often use Ry to identify scratches, dents, or pronounced tool marks that may affect sealing, contact stress, or visual quality. Even when average roughness values remain acceptable, an excessive Ry can indicate surface defects that cause functional or cosmetic issues.
RMS
RMS is a commonly used alternative term for Rq, particularly in legacy standards and older technical documentation. It evaluates surface roughness using a squared averaging method, which increases sensitivity to larger deviations from the mean line.
Because RMS emphasizes pronounced peaks and valleys more strongly than Ra, it appears in applications where surface energy, optical performance, or precision contact behavior is critical. Although less common on modern CNC drawings, RMS may still appear in customer specifications.
Rmax
Rmax identifies the single most extreme peak-to-valley distance found across the evaluated surface profile. Unlike average-based parameters, it focuses solely on the most severe surface irregularity.
This parameter is useful when a single defect could compromise performance, such as causing leakage, stress concentration, or visible surface damage. Engineers often reference Rmax to control outliers that average roughness values may fail to reveal.
Surface Finish Charts
Surface finish charts provide a practical reference that links roughness parameters with real manufacturing outcomes. Instead of reading Ra, Rz, or Rt as isolated numbers, charts translate these values into expected surface conditions, machining processes, and achievable quality levels. This makes them especially useful during early design stages, drawing reviews, and supplier discussions.
In CNC machining, surface finish charts help align design intent with manufacturing reality. They reduce guesswork, prevent over-specification, and make it easier to understand what a given roughness value actually means on a finished part.
Surface Roughness Conversion Chart (Ra, Rz, RMS)
| Ra (µm) | Rz (µm) | RMS / Rq (µm) | Typical Surface Description |
| 0.2 | 1.0 | 0.25 | Super-finished / mirror-like |
| 0.4 | 2.0 | 0.5 | Fine grinding or polishing |
| 0.8 | 4.0 | 1.0 | Precision machining |
| 1.6 | 6.3 | 2.0 | Standard CNC machining |
| 3.2 | 12.5 | 4.0 | General-purpose machining |
| 6.3 | 25.0 | 8.0 | Rough machining |
Surface Roughness Unit Conversion: Micrometers and Microinches
| Micrometers (µm) | Microinches (µin) | Common Usage Reference |
| 0.2 | 8 | Super-finished surfaces |
| 0.4 | 16 | Fine polishing or grinding |
| 0.8 | 32 | Precision CNC machining |
| 1.6 | 63 | Standard CNC machined finish |
| 3.2 | 125 | General-purpose machining |
| 6.3 | 250 | Rough machining surfaces |
| 12.5 | 500 | Coarse machined surfaces |
Common Standards for Surface Finish
In current ISO practice, surface finish is governed by the geometrical product specification (GPS) system, with surface roughness parameters defined and evaluated under the ISO 21920 series. This series represents the modern ISO framework for surface texture and replaces earlier standalone parameter standards. It defines how roughness characteristics such as Ra, Rz, and Rt are interpreted within the GPS and applied consistently in CNC machining.
Alongside ISO, ASME B46.1 remains widely used in inch-based CNC machining and legacy U.S. drawings. It defines surface texture parameters, measurement concepts, and symbol usage within the ASME system. While ISO and ASME describe similar physical surface characteristics, they differ in notation style, terminology, and historical conventions.
How to Measure Surface Roughness?
Surface roughness measurement turns surface texture into quantifiable data that designers, machinists, and inspectors can evaluate consistently. The method used matters because different techniques capture different aspects of the surface profile. In CNC machining, the choice of measurement method often depends on required accuracy, surface accessibility, and inspection speed.
Contact Measurement
Contact measurement uses a stylus profilometer that physically traces the surface of a CNC machined part. As the stylus moves along the machined surface, its vertical displacement records tool marks, peaks, and valleys to generate a surface profile.
This method is widely used for metal CNC components because it offers reliable accuracy and repeatability on flat, cylindrical, and rotational features. Access limitations and very soft materials can reduce its suitability.
Modern tactile surface texture sensors are designed for versatility and maximum flexibility. With multi-axis rotational capability, these systems can orient the profiler in virtually any direction, ensuring outstanding accessibility—even for parts with challenging geometries or hard-to-reach surfaces. Modular designs often feature several easy-to-change stylus arms, making it straightforward to adapt to a wide range of applications and component types. This adaptability means contact measurement remains a go-to technique for thorough and precise surface analysis across numerous industries.
Non-Contact Measurement
Non-contact measurement techniques use optical, laser, or interferometric systems to scan the surface of CNC parts without physical contact. These systems capture surface texture by analyzing reflected light or interference patterns.
These methods excel when dealing with delicate surfaces, soft materials, or complex geometries where traditional stylus access is challenging or could risk damage. Non-contact approaches generate zero physical traces, making them ideal for sensitive applications such as medical device components, polished metals, or intricate electronics.
2D and 3D Surface Analysis
Advanced non-contact systems can determine both 2D characteristic values and 3D surface parameters, revealing detailed microstructural properties. This includes comprehensive topography mapping, surface and area roughness measurements, and even layer thickness assessment—all performed with high precision and repeatability.
Key Advantages:
- No surface damage: Measurements are performed without altering or marking the sample, preserving even the most sensitive finishes.
- Large area coverage: High-numerical-aperture optics enable the capture of more data in a single scan, reducing the need for image stitching and minimizing artifacts.
- Versatility: Suitable for a wide range of materials, from laser-polished stainless steel to delicate separator foils in batteries.
- Quantitative and qualitative analysis: Capable of measuring features such as roughness, particle distribution, and microstructure over broad areas, with results that adhere to international standards.
Surface reflectivity, transparency, and environmental stability can influence measurement accuracy, so optimizing conditions for each material is essential. By leveraging these advanced optical techniques, manufacturers achieve precise, non-destructive insights into their components’ surfaces—supporting quality control, process optimization, and material innovation.
Comparison Methods
Comparison methods evaluate surface roughness by comparing the machined surface to reference specimens with known roughness values. These specimens are produced using standard machining or finishing processes.
This approach provides a quick qualitative assessment on the shop floor. It does not generate numerical data and is typically used for preliminary checks rather than final inspection.
- Useful for quick visual or tactile checks
- Suitable for preliminary inspection or production reference
- Not recommended as the only method for critical surfaces
- Should be supported by profilometer or CMM-based measurement when exact data is required
In-Process Measurement
In-process measurement monitors surface condition directly on the CNC machine during cutting. Sensors or probes assess changes in surface quality as machining progresses.
This method supports process control by identifying tool wear, vibration, or unstable cutting early. It is more common in high-volume or high-value CNC production than in final inspection.
Software Analysis and Reporting
Measuring surface roughness is only the first step. The data also needs to be filtered, calculated, visualized, and documented correctly. Surface analysis software helps turn raw measurement data into useful quality control information.
- Calculates parameters such as Ra, Rz, Rt, and Sa
- Generates surface profiles, charts, and inspection reports
- Supports batch comparison and process trend tracking
- Helps connect roughness data with quality documentation and process improvement
Microscopy-Based Measurement
Microscopy-based measurement examines the surface of CNC machined parts at high magnification using optical or electron microscopes. These techniques reveal fine surface features beyond the resolution of standard profilometers. They are mainly used for failure analysis, research, or ultra-precision components, rather than routine CNC inspection.
Accurate surface roughness evaluation depends not only on the measurement method but also on consistent measurement conditions, including sampling length, filtering, and alignment with the specified standard.
Some CNC machined surfaces require more detailed inspection than standard visual checks or contact roughness measurement can provide. Automated image analysis uses microscope images and software processing to detect small surface defects such as scratches, pits, burrs, or texture inconsistency.
This method helps reduce subjective judgment because the software can identify and measure surface features more consistently. It is useful for high-precision parts, research applications, medical components, and surfaces with very fine details.
- Optical microscopy shows visible defects, inclusions, and surface condition
- Laser scanning captures 3D topography and fine surface height changes
- Helps evaluate high-value or ultra-precision components
- Improves correlation between visual inspection and measured surface data
CMM-Based Roughness Measurement
Modern coordinate measuring machines (CMMs) can now incorporate roughness measurement directly into their automated inspection cycles, streamlining quality assurance for CNC machined parts. By equipping CMMs with specialized roughness probes—capable of evaluating surface finish in multiple directions—shops can assess dimensional features and surface texture within the same clamping and measuring sequence.
This integration offers several key advantages:
- All-in-One Inspection: Both geometric dimensions and roughness tolerances can be evaluated during a single, automated CMM run, providing complete inspection data that aligns with industry standards like ISO or ASME.
- Efficiency Gains: Eliminating the need for reclamping or transferring parts between machines reduces handling, minimizes setup time, and increases throughput, especially valuable in production settings.
- Flexibility and Accessibility: Modular probe systems and multi-axis heads enable measurement on complex features and hard-to-reach surfaces, accommodating diverse part geometries.
Integrating roughness assessment into the CMM cycle not only enhances process control but also supports consistent quality by reducing the risk of missed inspections or improper part handling. This approach is increasingly common in advanced CNC manufacturing environments seeking to optimize both accuracy and efficiency.
Advantages of Tactile Solutions for Curved Surfaces and Blisks
Tactile measurement—specifically with stylus profilometers—offers unique benefits when evaluating the surface roughness on blisks and other complex, curved workpieces. Here’s why this approach stands out in demanding applications:
- Accurate Capture of Intricate Geometries: Curved and concave surfaces, like those found between airfoil blades on blisks, are often difficult for non-contact systems to access effectively. Tactile probes, with various stylus shapes and slim profiles, can physically reach into tight or recessed features that would challenge optical solutions.
- Consistent and Repeatable Measurements: Because the stylus makes direct contact with the workpiece, results are less affected by surface reflectivity, transparency, or ambient lighting—common issues for laser or vision-based systems. This ensures reliable roughness data across a wide range of materials and finishes.
- Efficient Handling of High Measurement Volumes: Automated tactile systems can be programmed to perform multiple roughness checks in a single run. For blisk inspection, this means precise, repetitive measurement at various locations—streamlining quality control while reducing the chances of missed tolerances.
- Integration with Inspection Workflow: Tactile solutions are widely supported by modern measurement software. This makes it easy to manage large data sets, automate reporting, and flag out-of-tolerance results—making them practical for busy production environments.
For CNC machined blisks and other curved aerospace, energy, and automotive components, tactile roughness measurement remains a robust choice that balances accuracy, accessibility, and process efficiency.
What Factors Influence Surface Finish and How to Improve?
Surface finish on CNC machined parts is not determined by a single variable. It results from the combined effect of machine capability, cutting conditions, tooling, material behavior, and process control. Understanding these factors makes it possible to predict surface quality more accurately and improve it without unnecessary secondary operations.
Cutting Parameters
Cutting parameters directly shape the surface left on CNC machined parts. Feed rate controls tool mark spacing, with higher feeds producing rougher textures and lower feeds creating finer finishes. Cutting speed influences heat and chip formation, which affects surface tearing or smearing. Depth of cut impacts stability, where excessive engagement often leads to vibration and chatter marks.
To improve surface finish, reduce feed rate during finishing passes, select cutting speeds suited to the material, and use shallow, stable cuts for final operations.
Coolant and Lubrication
Coolant and lubrication affect surface finish by controlling heat, friction, and chip evacuation at the cutting interface. Insufficient lubrication increases friction and accelerates tool wear, which quickly degrades surface quality.
Proper coolant application helps stabilize cutting conditions, reduces built-up edge formation, and improves surface consistency. In some materials, switching from dry cutting to minimum quantity lubrication (MQL) significantly improves surface appearance and repeatability.
Machining Process Type
Different CNC processes naturally produce different surface finishes. Turning typically generates more uniform finishes on rotational features, while milling introduces directional tool marks influenced by tool path strategy. Drilling and boring often result in rougher internal surfaces without secondary operations.
Selecting the right process for the feature is critical. For example, finishing bores with reaming or honing produces far better surface quality than drilling alone. Matching surface requirements with the most suitable process reduces reliance on costly post-processing.
Machine Rigidity and Vibration
Machine rigidity plays a major role in surface finish stability. Flexibility in the machine structure, fixturing, or workpiece allows vibration to develop, which appears as waviness or chatter marks on the surface.
Improving rigidity through proper fixturing, shorter tool overhangs, and stable clamping often leads to immediate surface finish improvements. Even small reductions in vibration can significantly enhance surface consistency.
Tool Condition
Tool condition has a direct and visible impact on surface finish. Worn cutting edges increase friction, smear material, and leave irregular marks on the surface. Chipped or damaged tools often produce inconsistent roughness that cannot be corrected through parameter adjustment alone.
Maintaining sharp tools, using appropriate tool coatings, and replacing tools before excessive wear develops are among the most effective ways to control surface finish. In finishing operations, tool quality often matters more than machine capability.
How to Choose the Right Surface Finish Technology?
Choosing the right surface finish technology means matching functional needs with material behavior and operating conditions. The goal is not to achieve the smoothest surface possible, but the surface that performs reliably while remaining practical to manufacture. In CNC machining, this decision directly affects cost, lead time, and long-term part performance.
Functional Requirements
Functional requirements define what the surface must do in service, and they are the most important factor when selecting surface finish technology. Different functions impose different demands on surface texture, friction behavior, wear resistance, and compatibility with secondary processes. Choosing surface finish based on function helps avoid both over-processing and performance risk.
- Structural or non-contact surfaces: As-machined CNC finish is usually sufficient, as surface texture has little impact on performance.
- Sliding or rotating interfaces: Fine CNC finishing passes or grinding are commonly used to reduce friction and ensure stable motion.
- Sealing surfaces: Controlled machined finishes or light grinding provide the surface texture needed for proper seal deformation.
- Wear-critical or load-bearing surfaces: Grinding, honing, or controlled finishing operations help minimize sharp asperities and improve durability.
- Surfaces requiring coating or plating: Uniform machined finishes or light surface preparation support consistent coating adhesion.
- Cosmetic or visible components: Bead blasting, brushing, polishing, or anodizing improve visual consistency and perceived quality.
Material Type
Material type defines how the surface is formed during cutting and how much finishing effort is required. Hardness, ductility, and heat behavior all affect achievable surface quality, so surface finish technology must adapt to the material rather than follow a fixed rule.
- Aluminum alloys: Machine cleanly and allow a wide finish range. As-machined finishes are often sufficient, with bead blasting or anodizing used for appearance.
- Carbon steel and alloy steel: Respond well to controlled finishing passes. Grinding or coating is added when functional or protective requirements exist.
- Stainless steel: Heat and work hardening make surface control harder. Stable finishing or grinding helps maintain consistency.
- Titanium and hard alloys: Limited finish capability from machining alone. Light finishing combined with grinding or polishing is common.
- Engineering plastics: Sensitive to heat and deformation. Sharp tools and light finishing passes produce the best results.
Friction and Wear Conditions
Friction and wear conditions define which surface finishing processes perform best in service, not just how smooth the surface should look. Different operating conditions favor different surface textures and finishing technologies. Selecting the right surface treatment helps control wear, reduce friction, and extend component life.
- Continuous sliding motion: Fine CNC finishing, grinding, or honing to reduce friction and stabilize motion.
- Intermittent or start–stop motion: Controlled machined finishes or light grinding to limit stick-slip effects.
- Lubricated interfaces: Fine machining or grinding with moderate roughness to support lubricant retention.
- Dry or low-lubrication conditions: Grinding or polishing to reduce direct surface contact and wear.
- High-load or abrasive environments: Grinding, honing, or hard surface treatments combined with controlled roughness.
Conclusion
Surface finish plays a critical role in how CNC machined parts perform, last, and are perceived. Understanding surface roughness parameters, symbols, measurement methods, and standards makes it easier to interpret surface finish charts and apply them correctly. More importantly, surface finish should always be selected based on functional requirements, material behavior, and operating conditions—not on arbitrary roughness values.
At DZ Making, surface finish is treated as an integral part of the machining process rather than a secondary step. From machining strategy selection to surface treatment execution, surface quality is planned and controlled to match real application requirements and production constraints.
