01
Surface-zone map
Classify primary visible, secondary visible, hidden and functional surfaces with different allowable conditions where appropriate.
Evidence route
Marked-up drawing or zone map with acceptance class
Visual surface control
Cosmetic sheet metal: turn appearance into an inspectable requirement.
Scratches, grain variation, weld dressing, brake lines, colour, gloss and handling marks cannot be released consistently through words such as ‘good finish’. PartVerity defines surface zones, process history, samples and viewing conditions before appearance becomes a supplier dispute.
Decision premise
Cosmetic question: which surfaces matter, what defects are allowed, and under which repeatable conditions is the decision made?
Engineering control
Six controls for cosmetic sheet-metal acceptance
Visual acceptance is separate from dimensional acceptance. Both can be required, and neither should silently override the other.
02
Material and grain direction
Define brushed, mill, polished or protected surface state and preserve directional grain through nesting and forming.
Evidence route
Surface designation, face and grain arrows
03
Process-mark criteria
Address brake lines, tool marks, weld dressing, edge witness, sink or print-through by zone and process route.
Evidence route
Defect catalogue, limit sample or annotated images
04
Handling and protection
Plan film, separators, gloves, rack contact, packaging and transfer points from stock through coating and shipment.
Evidence route
Handling/packaging instruction and final condition record
05
Viewing conditions
Set lighting type, intensity if critical, distance, angle and inspection duration so judgement is repeatable.
Evidence route
Visual-inspection work instruction and result
06
Sample and authority
Control approved samples by revision/date and define who may accept borderline conditions or require rework.
Evidence route
Golden/limit sample identity, deviation link and release owner
Decision matrix
Cosmetic condition to acceptance method
A photograph can support communication but may not reproduce colour, gloss, texture or viewing conditions accurately.
| Cosmetic condition | Acceptance basis | Evidence focus |
|---|---|---|
| Directional brushed surface | Controlled grain and limit sample | Orientation, uniformity and protected handling |
| Powder-coated enclosure | Exact system plus physical colour/texture sample | Coverage, colour, gloss, defects and contact marks |
| Visible welded corner | Joint/dressing standard and sample | Profile, witness marks and surrounding distortion |
| Hidden internal face | Defined lower visual class with functional limits | Burr, contamination and assembly risk |
| Brand-critical front panel | Primary zone, viewing standard and named authority | Sample identity and documented disposition |
Claim boundaries
Weak cosmetic acceptance language
‘No scratches’ without defining surface zones and viewing conditions.
A digital colour reference without physical sample control.
Accepting appearance before final forming, welding or coating.
Using cosmetic approval to waive dimensional or functional non-conformance.
Technical context
Use guidance to frame the review—not to replace project evidence.
External context for cosmetic brake lines, secondary blending, protection during forming and finish interaction. Project visual criteria require controlled samples or standards.
Protolabs sheet-metal design guidelines