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Clear Coating

Coatings for plastics · Spray applied

Clear coating is a transparent liquid topcoat used to protect color, graphics, and prepared printed-polymer surfaces while controlling gloss.

3D printingStandard cost $$Insulating
Request Clear coat on a partCompare coatings for plastics

Reference page — Clear coat is not in the instant-quote configurator. Upload the part, name the finish in the notes, and an engineer quotes it with the part.

Clear Coating on a machined part

What is Clear coat?

Acrylic, polyurethane, and lacquer chemistries differ in hardness, weathering, solvent resistance, and cure.

How it works

The printed part is cleaned, dried, and often sealed or primed to prevent uneven absorption. A transparent resin is sprayed in controlled coats, allowed to flash, and cured by solvent evaporation, chemical crosslinking, heat, or another product-specific mechanism. The clear film levels surface texture and isolates the substrate from handling and stains. It does not hide layer lines or color nonuniformity unless those defects are corrected before coating.

Why specify it

  • Protects dye, paint, decals, and printed surfaces
  • Controls matte, satin, or high-gloss appearance
  • Can improve cleanability and light scratch resistance
  • Transparent film preserves underlying color

Where it falls short

  • Clear film highlights rather than hides surface defects
  • Some products yellow under ultraviolet or heat exposure
  • Solvents can attack printed polymers
  • Edges can chip or peel when adhesion is poor

Clear coat at a glance

Clear coat is strongest on cosmetic quality (85 of 100), at a standard cost. It adds little surface hardness.

Corrosion protectionLow20 / 100
Surface hardnessMinimal12 / 100
Cosmetic qualityExcellent85 / 100
LubricityLow20 / 100
Relative costStandard25 / 100
CorrosionHardnessCosmeticLubricityEconomy

Each score is 0–100 against every finish in this catalog. Corrosion comes from salt-spray life (ASTM B117, log scale) and hardness from the finish layer's Vickers or pencil hardness; cosmetic, lubricity and cost are FabDigit's engineering assessment. Economy on the radar is the inverse of cost.

Clear coat key numbers

Typical values from the governing specifications and shop practice; bars are this finish against the highest value among coatings for plastics finishes.

Thickness15–50 µm0.59–2 mil
Thickness
15–50 µm for a liquid clear topcoat; product data sheet controls
Hardness
H–2H pencil hardness (ASTM D3363) — two-component polyurethane clearcoat
Electrical
Insulating
Colours
  • clear
Appearance
Transparent matte through high gloss; substrate texture and color remain visible.

Where Clear coat sits among all finishes

Surface hardness (Vickers, log scale) against corrosion protection (salt-spray hours, log scale) for every coating FabDigit offers, one cloud per finish group. Clear coat is highlighted; hover a dot for its name or open the full map.

02550751000255075100Corrosion protection (0–100)Surface hardness (HV, log scale, 0–100)Plating — 19 finishesHard coatings — 17 finishesAnodize & conversion — 8 finishesPaint & powder — 7 finisheshard, low corrosion protectionhard and protectiveprotective, softsoft, little protectionType II anodize — corrosion 71, hardness 54BSA anodize — corrosion 71, hardness 52Type I anodize — corrosion 71, hardness 49Hard anodize — corrosion 71, hardness 61PTFE hard anodize — corrosion 71, hardness 61Nitriding — corrosion 55, hardness 73PEO — corrosion 70, hardness 74Sherardizing — corrosion 83, hardness 56Brass plate — corrosion 35, hardness 44Bronze plate — corrosion 40, hardness 49Cadmium plate — corrosion 70, hardness 26Copper plate — corrosion 32, hardness 39Decorative chrome — corrosion 64, hardness 71Electroless copper — corrosion 20, hardness 41Electroless nickel — corrosion 70, hardness 68Nickel plate — corrosion 51, hardness 55Gold plate — corrosion 68, hardness 39Hard chrome — corrosion 40, hardness 73Hot-dip zinc — corrosion 90, hardness 42Nickel-PTFE — corrosion 72, hardness 57Silver plate — corrosion 55, hardness 39Solder plate — corrosion 42, hardness 9Tin plate — corrosion 34, hardness 0Zinc plate — corrosion 60, hardness 30Zinc-nickel — corrosion 86, hardness 60Cerakote — corrosion 83, hardness 27E-coat — corrosion 83, hardness 15Epoxy coat — corrosion 83, hardness 15Powder coat — corrosion 83, hardness 14Wet paint — corrosion 59, hardness 10AlCrN PVD — corrosion 58, hardness 93AlTiN PVD — corrosion 52, hardness 94CrN PVD — corrosion 62, hardness 83DLC — corrosion 55, hardness 93MoS2 PVD — corrosion 20, hardness 26TiAlN PVD — corrosion 50, hardness 93TiCN PVD — corrosion 40, hardness 92TiB2 PVD — corrosion 40, hardness 94TiN PVD — corrosion 45, hardness 87WC/C PVD — corrosion 48, hardness 77ZrN PVD — corrosion 52, hardness 90CVD alumina — corrosion 70, hardness 85CVD TiCN — corrosion 38, hardness 92CVD TiN — corrosion 45, hardness 87Multilayer CVD — corrosion 62, hardness 88HVOF coating — corrosion 78, hardness 77Plasma spray — corrosion 60, hardness 68Plastic chrome — corrosion 72, hardness 71Electroless plastic — corrosion 58, hardness 39Soft-touch — corrosion 20, hardness 5PLATINGHARD COATINGSANODIZE & CONVERSIONPAINT & POWDERType II anodizePowder coatZinc plateZinc-nickelHard chromeDLCTiN PVDTin plateCadmium plateE-coatCerakoteWet paintHot-dip zincNitridingHVOF coatingClear coat — corrosion 20, hardness 12Clear coat
02550751000255075100Corrosion protection (0–100)Surface hardness (HV, log scale, 0–100)Plating — 19 finishesHard coatings — 17 finishesAnodize & conversion — 8 finishesPaint & powder — 7 finishesType II anodize — corrosion 71, hardness 54BSA anodize — corrosion 71, hardness 52Type I anodize — corrosion 71, hardness 49Hard anodize — corrosion 71, hardness 61PTFE hard anodize — corrosion 71, hardness 61Nitriding — corrosion 55, hardness 73PEO — corrosion 70, hardness 74Sherardizing — corrosion 83, hardness 56Brass plate — corrosion 35, hardness 44Bronze plate — corrosion 40, hardness 49Cadmium plate — corrosion 70, hardness 26Copper plate — corrosion 32, hardness 39Decorative chrome — corrosion 64, hardness 71Electroless copper — corrosion 20, hardness 41Electroless nickel — corrosion 70, hardness 68Nickel plate — corrosion 51, hardness 55Gold plate — corrosion 68, hardness 39Hard chrome — corrosion 40, hardness 73Hot-dip zinc — corrosion 90, hardness 42Nickel-PTFE — corrosion 72, hardness 57Silver plate — corrosion 55, hardness 39Solder plate — corrosion 42, hardness 9Tin plate — corrosion 34, hardness 0Zinc plate — corrosion 60, hardness 30Zinc-nickel — corrosion 86, hardness 60Cerakote — corrosion 83, hardness 27E-coat — corrosion 83, hardness 15Epoxy coat — corrosion 83, hardness 15Powder coat — corrosion 83, hardness 14Wet paint — corrosion 59, hardness 10AlCrN PVD — corrosion 58, hardness 93AlTiN PVD — corrosion 52, hardness 94CrN PVD — corrosion 62, hardness 83DLC — corrosion 55, hardness 93MoS2 PVD — corrosion 20, hardness 26TiAlN PVD — corrosion 50, hardness 93TiCN PVD — corrosion 40, hardness 92TiB2 PVD — corrosion 40, hardness 94TiN PVD — corrosion 45, hardness 87WC/C PVD — corrosion 48, hardness 77ZrN PVD — corrosion 52, hardness 90CVD alumina — corrosion 70, hardness 85CVD TiCN — corrosion 38, hardness 92CVD TiN — corrosion 45, hardness 87Multilayer CVD — corrosion 62, hardness 88HVOF coating — corrosion 78, hardness 77Plasma spray — corrosion 60, hardness 68Plastic chrome — corrosion 72, hardness 71Electroless plastic — corrosion 58, hardness 39Soft-touch — corrosion 20, hardness 5PLATINGHARD COATINGSANODIZE & CONVERSIONPAINT & POWDERPowder coatZinc plateClear coat — corrosion 20, hardness 12Clear coat
Anodize & conversionPlatingPaint & powderHard coatings

Specifications for Clear coat

The documents a drawing cites to define this finish, with the Type / Class rows that apply. Each links to a page explaining the standard.

Drawing call-out

CLEAR 2K POLYURETHANE TOPCOAT, NON-YELLOWING GRADE, 25–40 µm DFT, 80–90 GU AT 60°; MASK THREADS, SNAP FEATURES, AND OPTICAL DATUMS

Which materials take Clear coat?

Verdict per material family, with the grades that behave differently. Each family links to its datasheets in the material library.

Material familyVerdictNotes
Aluminum
YesCommon over conversion coating, anodize, or primer.
Polymer
YesSelect chemistry for the exact polymer.
SLA
YesFully post-cure, sand, and clean before coating.
Steel
YesCommon over phosphate, primer, or cleaned bare steel.
Brass
With careClean tarnish and qualify adhesion.
Composite
With careSeal porosity before clear coating.
Copper Alloy
With careClean tarnish and qualify adhesion; some solvents stain copper.
FDM
With careSeal layer lines first; solvent clears can craze some FDM resins.
Magnesium Alloy
With careNeeds conversion coating or primer before an organic film.
MJF
With careSurface texture and dark base color remain visible.
SLS
With carePorous nylon needs sealing and surface preparation.
Stainless Steel
With careNeeds mechanical or chemical activation for adhesion.
Titanium
With careNeeds activation or primer for organic films.
Zinc Alloy
With careNeeds conversion coating or primer; some solvents attack zinc.
DMLS / SLM
LimitedOnly as a temporary appearance or isolation film on metal AM.

How Clear coat is applied, and what it does to the part

  1. 1Clean
  2. 2Sand and seal if required
  3. 3Mask
  4. 4Apply clearcoat
  5. 5Flash
  6. 6Apply additional coat if specified
  7. 7Cure
  8. 8Inspect transparency and gloss
DimensionsAllow 15–50 µm per face; clearcoat can bind snap fits and reduce optical dimensional accuracy.
Build-up per side15–50 µm — Adds the cured transparent film thickness.
MaskingUsually needed. Mask threads, snaps, optical datum surfaces, adhesive zones, and electrical contacts.
ElectricalInsulating
AppearanceTransparent matte through high gloss; substrate texture and color remain visible.
Added lead time3–7 working days on top of the bare part

Design rules for Clear coat

What to decide on the drawing before the part goes to the finisher.

  1. Specify resin chemistry, not only 'clear'.Acrylic, polyurethane, and lacquer have different durability.
  2. Define gloss at a measurement angle.Words such as satin do not provide a testable range.
  3. Prepare the substrate to final cosmetic quality first.Transparent film magnifies scratches, dust, and layer lines.
  4. Run solvent compatibility testing on the actual print resin.Some clearcoat carriers craze or soften printed polymers.

Clear coat versus the alternatives

Finishes engineers weigh against Clear coat, and when each wins.

FinishCorrosionHardnessCosmeticCostThicknessChoose it when
Clear coat
this page
201285$$15–50 µm—
UV-Cured Coating
Clear coat vs UV-Cured Coating →
25—90$$10–30 µmwhen rapid UV cure and a harder thin plastic topcoat are required
Tinted Clear Coating
Clear coat vs Tinted Clear Coating →
15—92$$15–50 µmwhen transparent color adjustment is needed
CorrosionHardnessCosmeticLubricityEconomy
Clear coatUV-Cured Coating

The radar overlays Clear coat with UV-Cured Coating, its most common alternative — chosen when rapid UV cure and a harder thin plastic topcoat are required. Scores in the table are 0–100 across every finish in the catalog.

Cost, lead time and compliance

Relative cost

Clear Coating is a standard-cost finish ($$): cheaper than about 71 % of the finishes FabDigit quotes.

Finishing is priced per part with a lot minimum, from FabDigit's own China-side rates. The exact figure appears on the instant quote once the part is uploaded.

Lead time and compliance

Added lead time3–7 working days
RoHSCompliant
NotesCompliance and VOC content depend on the selected clearcoat.

What Clear coat is used for

  • Painted prototypes
  • Dyed printed parts
  • Display models
  • Decal protection
  • Consumer housings

Clear coat — frequently asked

what clear coat should I use on 3D prints

Choose a product explicitly compatible with the print polymer and desired gloss. A 15–50 µm polyurethane or acrylic-class film is common, but test for softening, crazing, and adhesion first.

does clear coat hide layer lines

No. It may slightly level a prepared surface, but transparent film usually makes remaining scratches and layer lines more visible. Sand and seal before coating.

how thick is clear coat

A broad liquid clearcoat range is 15–50 µm dry film. The selected chemistry and coat count should narrow that range on the drawing.

does clear coat yellow

Some resins yellow under heat or ultraviolet exposure. Specify a non-yellowing outdoor-grade product and validate color shift when appearance is critical.

can clear coat affect snap fits

Yes. A 15–50 µm layer on both mating faces reduces clearance by 30–100 µm. Mask functional snaps or design coating allowance.