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Chemical Etching

Marking & decoration · Chemical bath

Chemical etching uses a patterned resist and material-specific etchant to recess graphics or create a frosted contrast.

CNC machiningSheet metalInjection moldingPremium cost $$$Unchanged
Quote a part with Chemical etchCompare marking & decoration
Chemical Etching on a machined part

What is Chemical etch?

It is used for fine scales, logos, nameplates, decorative patterns, and durable identification.

How it works

The surface is cleaned and coated with a resist. Artwork is transferred by photographic exposure, printing, or masking, and the exposed substrate is contacted by an etchant selected for the metal, glass, ceramic, or polymer. Dissolution creates a recessed or roughened image; the part is then rinsed, neutralized, stripped, and optionally colour-filled. Etch rate and lateral undercut depend on chemistry, temperature, agitation, time, and substrate composition.

Why specify it

  • Creates fine patterns without cutting force
  • Can process multiple marks in a panel batch
  • Typical decorative depth is 5–100 µm
  • Works on flat sheets, nameplates, glass, and selected formed parts

Where it falls short

  • Chemistry is substrate-specific and tightly controlled
  • Etching undercuts the resist and rounds fine details
  • Waste treatment and chemical handling are required
  • Deep marks take longer and lose edge definition

Chemical etch at a glance

Chemical etch is strongest on cosmetic quality (76 of 100), at a premium cost. It adds little corrosion protection or lubricity. Surface hardness is not rated: the finish leaves the part's own surface.

Corrosion protectionMinimal0 / 100
Surface hardnessNot rated—
Cosmetic qualityVery good76 / 100
LubricityMinimal10 / 100
Relative costPremium40 / 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.

Chemical etch key numbers

Typical values from the governing specifications and shop practice; bars are this finish against the highest value among marking & decoration finishes.

Thickness5–100 µm0.2–3.9 mil
Thickness
5–100 µm recessed mark depth; frosted glass or polymer effects may be shallower and are process-specific.
Electrical
Unchanged
Colours
  • substrate contrast
  • optional paint fill
Appearance
Recessed matte, frosted, or colour-filled graphics with chemically rounded edges.

Specifications for Chemical etch

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

CHEMICALLY ETCH LOGO AND SCALE 0.025–0.050 MM DEEP, 0.20 MM MIN LINE WIDTH, BLACK EPOXY FILL, LOCATION ±0.25 MM

Which materials take Chemical etch?

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

Material familyVerdictNotes
Aluminum
YesRequires aluminum-compatible resist and etchant.
Brass
YesCommon nameplate and decorative etch substrate.
Copper Alloy
YesCommon for nameplates and decorative work.
Glass
YesHF or fluoride frost etching is a standard glass mark, with strict handling controls.
Stainless Steel
YesPost-cleaning and passivation review may be needed.
Steel
YesCommon for plates and scales; prevent flash rust after processing.
Magnesium Alloy
With carePossible with a magnesium-safe etchant; rinsing must be immediate to avoid corrosion.
Titanium
With careRequires a titanium-specific etchant and tight process control.
Zinc Alloy
With careEtches quickly; control time to avoid undercut and staining.
Polymer
LimitedSelected plastics (for example acrylic) can be frosted; most engineering resins do not etch cleanly.

How Chemical etch is applied, and what it does to the part

  1. 1Clean surface
  2. 2Apply resist
  3. 3Image and develop artwork
  4. 4Etch
  5. 5Rinse and neutralize
  6. 6Strip resist
  7. 7Fill colour if specified
  8. 8Inspect depth and undercut
DimensionsEtching removes 5–100 µm in exposed areas and also creates lateral undercut beneath resist edges.
MaskingUsually needed. Resist must protect every area not intended for etching, including edges, holes, threads, and sealing faces.
ElectricalUnchanged
AppearanceRecessed matte, frosted, or colour-filled graphics with chemically rounded edges.
Added lead time4–8 working days on top of the bare part

Design rules for Chemical etch

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

  1. Use 0.20 mm minimum line width unless the etcher approves finer artwork.Lateral undercut erodes narrow resist features.
  2. Specify substrate grade and any coating.Etchant and rate depend on composition.
  3. Keep fine artwork away from exposed edges and deep recesses.Etchant flow and resist coverage become nonuniform.
  4. State depth and whether colour fill is required.Frosting, shallow etch, and deep recess are different processes.

Chemical etch versus the alternatives

Finishes engineers weigh against Chemical etch, and when each wins.

FinishCorrosionHardnessCosmeticCostThicknessChoose it when
Chemical etch
this page
0—76$$$5–100 µm—
Electrochemical Etching
Chemical etch vs Electrochemical Etching →
0—55$$2–25 µmfor localized conductive-metal marks
Laser Marking
Chemical etch vs Laser Marking →
0—70$0–50 µmfor variable data without wet chemistry
CorrosionHardnessCosmeticLubricityEconomy
Chemical etchElectrochemical Etching

The radar overlays Chemical etch with Electrochemical Etching, its most common alternative — chosen for localized conductive-metal marks. Scores in the table are 0–100 across every finish in the catalog.

Cost, lead time and compliance

Relative cost

Chemical Etching is a premium-cost finish ($$$): cheaper than about 55 % 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 time4–8 working days
RoHSCompliant
NotesThe finished mark can be compliant, but etchants, resist strippers, rinse water, and dissolved metals require controlled handling and waste treatment.

What Chemical etch is used for

  • Instrument scales
  • Metal nameplates
  • Glass legends
  • Decorative panels
  • Logos and regulatory text

Chemical etch — frequently asked

Chemical etching vs laser marking: which is better?

Chemical etching can batch broad fine patterns and create a 5–100 µm recess without tool force. Laser marking is better for variable serial data and avoids resist and wet chemistry.

How deep is a chemical etched mark?

A practical decorative marking range is about 5–100 µm. Depth and undercut depend on alloy, chemistry, temperature, agitation, and etch time.

Can chemical etching mark stainless steel?

Yes, with stainless-compatible resist and etchant followed by thorough neutralization and cleaning. If corrosion performance matters, review whether passivation is required after etching.

Can glass be chemically etched for labels?

Yes, chemical frosting can create durable matte legends, but glass etchants require specialized hazardous-chemical controls. Specify artwork, contrast, depth or frosting appearance, and protected areas.

Can chemical etched marks be colour filled?

Yes. The recessed 5–100 µm image can retain paint or epoxy, but fill chemistry, cure, wipe method, and adhesion test must be specified.