Product developers often ask us which plastics work best for laser marking — and for good reason. After years of marking everything from medical device housings to audio equipment faceplates, we’ve seen how material choice dramatically affects contrast, durability, and overall part quality. The wrong plastic-laser combination can result in poor readability, heat damage, or even structural weakness.
ABS, polycarbonate (PC), and nylon provide excellent laser marking contrast and clarity. Most thermoplastics can be marked, but avoid PVC and some fluoropolymers due to toxic fumes. CO₂ lasers work best for most plastics, creating white or light marks on dark materials.
Discover materials that mark cleanly, and get tips on laser type, text size, and specs to ensure accurate, durable part marking from the start.
Table of Contents
Which plastics give the best contrast and clarity when laser marked?
ABS offers the best overall contrast for laser marking, creating bright white marks on black parts with 80%+ contrast ratios. Polycarbonate (PC) and nylon also deliver excellent readability, while avoid PP and PE for critical markings – they produce poor contrast that fails readability standards for serial numbers or barcodes.
From our experience marking thousands of plastic parts, ABS consistently produces the sharpest, most durable marks. When we laser mark black ABS housings for audio equipment, the resulting white text contrasts beautifully against the dark surface. PC behaves similarly but can yellow slightly under high power settings. Nylon creates a dark mark on natural-colored material, which works well for industrial applications where high contrast isn’t critical.
Material color significantly impacts marking quality. Dark plastics like black ABS or PC create bright white marks that are easily readable. Clear or translucent materials often produce faint marks that disappear under certain lighting conditions. White or light-colored plastics can be challenging — the laser typically creates a slight color change rather than high contrast. Note that flame retardants and glass-filled additives can reduce contrast by up to 30%.
| Material | Contrast Quality | Best Applications | Avoid For |
|---|---|---|---|
| ABS | Excellent (80%+) | Serial numbers, logos | None |
| PC | Excellent (75%+) | Medical housings | High-power marking |
| Nylon | Good (60%+) | Industrial parts | High-contrast needs |
| PP | Poor (20%-) | Non-critical marking | Barcodes, part numbers |
| PE | Poor (15%-) | Basic identification | Any critical marking |
Design Takeaway: Choose dark-colored ABS or PC when laser marking is required for optimal contrast. Never specify PP or PE for part numbers or barcodes – they’ll fail inspection standards. If your design requires light-colored plastics, consider adding a small dark marking area or using alternative identification methods like labels or molded-in features.
What laser type works best for marking my plastic material?
CO₂ lasers handle 90% of ABS and PC marking jobs with standard contrast quality. Fiber lasers are needed for nylon or additive-filled plastics, while UV marking adds 50-100% to marking cost but delivers superior quality on challenging materials like PP.
From our experience, CO₂ lasers work well for most thermoplastics like ABS and PC, creating white foaming marks on dark surfaces. Fiber lasers are required for nylon or when laser additives are present in the plastic compound. UV lasers provide exceptional quality on difficult materials but significantly increase lead time and cost.
Never specify UV for standard ABS or PC unless surface integrity is absolutely critical – the cost premium rarely justifies the quality gain. For challenging materials like PP or PE, mention this upfront so we can recommend adding laser-sensitive additives to your plastic compound. Avoid marking on walls thinner than 0.5mm to prevent burn-through or warping.
| Material | Recommended Process | Cost Impact | Lead Time |
|---|---|---|---|
| ABS/PC | CO₂ standard | Baseline | 1-2 days |
| Nylon | Fiber laser | +20-30% | 2-3 days |
| PP/PE | UV required | +50-100% | 3-5 days |
Design Takeaway: Don’t specify laser type in your RFQ. Instead, clearly define marking requirements (contrast level, text size, surface quality) and let us recommend the most cost-effective process for your material.
Can I mark logos, barcodes, or part numbers directly on the molded surface?
Simple logos mark adequately on molded surfaces, but barcodes and part numbers require machined flat areas for reliable scanning. Textured injection-molded surfaces create uneven marking depth that causes barcode scanning failures and makes fine text difficult to read.
We routinely machine 0.1-0.2 mm deep pockets or raised pads for marking areas when consistent quality is required. This provides the smooth reference surface needed for crisp marking, especially for part numbers and barcodes that require scanner readability. The machined area should be 2-3 mm larger than the marking footprint to allow for setup tolerance.
Position marking areas at least 3 mm away from ribs, bosses, and parting lines to avoid shadows during laser setup. Gate locations often create surface irregularities that interfere with marking consistency. Linear barcodes need 3x3mm minimum, QR codes need 5x5mm for reliable scanning. Molded surfaces with Ra <2.0μm may work without machining for simple text, but we recommend machining flats for any critical marking.
Position marking areas ±0.5mm from reference edges like machined faces or molded datum features. For multiple marking locations, create a marking layout drawing showing all areas with consistent depth and finish requirements.
Quick Decision:
- ✅ Logos on smooth molded surfaces (Ra <2.0μm) → Use as-is
- ❌ Barcodes/QR codes on any textured surface → Specify machined flat area
- ❌ Multiple marking areas → Create marking layout drawing
- ❌ Marking near ribs/bosses → Relocate ≥3mm away or machine flat
Design Takeaway: Call out machined marking areas in your drawings with Ra ≤1.6 μm surface finish and ±0.5mm position tolerances from reference features. This eliminates marking quality issues and ensures consistent barcode scanning in production.
What's the smallest text size that stays readable after laser marking?
0.5mm character height minimum for reliable readability on most plastics. Characters smaller than this often become blurred or filled-in, especially on textured surfaces or when viewing from normal working distances.
From our marking experience, character height drives readability more than font choice. We consistently achieve sharp 0.5mm text on smooth ABS and PC surfaces. On nylon, minimum readable size increases to 0.7mm due to the material’s tendency to create wider mark lines. Dark materials with white marking provide better small-text readability than light materials with dark marking.
Line width matters as much as height. Maintain stroke width between 0.1-0.15mm for optimal clarity – thinner lines disappear, thicker lines blur together. For serial numbers and part codes, we recommend 0.8mm character height to ensure consistent readability across production lots and different operators. Use simple sans-serif fonts like Arial for small text – serif fonts and complex characters become unreadable below 1.0mm.
Character spacing is critical below 1.0mm height. Allow at least 0.2mm between characters to prevent fill-in. Long text strings (>8 characters) should use larger sizing since cumulative spacing errors reduce overall readability. Expect ±0.1mm variation in character size across production batches due to material and process variations.
| Surface Type | Minimum Height | Recommended Height | Best For |
|---|---|---|---|
| Smooth ABS/PC | 0.5mm | 0.8mm | Serial numbers, dates |
| Textured surfaces | 0.7mm | 1.0mm | Part numbers, logos |
| Nylon materials | 0.7mm | 1.0mm | Industrial marking |
Design Takeaway: Specify 0.8mm minimum character height for production parts to account for material variation and operator readability. Avoid text strings longer than 10 characters at minimum sizing – break into multiple lines instead.
How deep does laser marking penetrate, and will it weaken the part?
Laser marking typically penetrates 0.01-0.05mm deep, which is negligible for structural integrity on walls thicker than 1.0mm. However, avoid marking near stress concentrations like living hinges, snap fits, or sharp corners where even shallow marks can initiate crack propagation.
From our experience with marked parts, depth varies by material and laser type. CO₂ laser foaming creates raised marks with minimal penetration, while fiber lasers etch slightly deeper into the surface. On thin-walled parts (0.5-1.0mm), we position marking away from high-stress areas based on part geometry and loading.
Keep marking at least 3mm away from living hinges, snap fits, and sharp internal corners. For walls thinner than 0.8mm, we recommend relocating marking to thicker sections or using alternative identification methods like laser-etchable labels or molded-in raised numbers. Glass-filled variants (especially 30%+ content) are more sensitive due to fiber-end exposure during marking.
Wall Thickness Guidelines:
- >2.0mm walls → Mark anywhere except near stress concentrations
- 1.0-2.0mm walls → Avoid high-stress areas, keep >3mm from corners
- 0.5-1.0mm walls → Mark only in low-stress areas, consider alternatives
- <0.5mm walls → Use labels or molded-in identification instead
Quick Decision:
- ✅ Walls >1.0mm, away from stress points → Safe to mark
- ❌ Near living hinges or snap fits → Relocate ≥3mm away
- ❌ 30% glass-filled materials → Extra clearance from stress points
- ❌ Critical load-bearing areas → Consider testing or alternatives
Design Takeaway: Position marking in low-stress areas on walls >1.0mm thick. Never mark directly on living hinges, snap fits, or within 3mm of sharp corners. For critical structural parts, consider tensile testing if marking near load-bearing areas and specify marking location in your drawings to avoid problematic placement.
Can laser marking be done after other processes like painting or coating?
Mark before coating for best results – marking through coatings requires 20-40% higher power and reduces contrast quality. Marking through paint or coatings requires precise power settings to avoid damaging the underlying plastic, and contrast quality is often reduced compared to direct plastic marking.
From our experience, sequence matters significantly. Anodizing after marking often creates color variations in marked areas, while powder coating typically prevents effective marking due to thickness. Paint removal marking creates excellent contrast by selectively ablating surface layers to expose the base material color. This works well for automotive buttons where day/night visibility is required.
Marking through existing coatings requires 20-40% higher laser power and may cause heat damage or coating delamination around the marked area. Thin spray paints (<25μm) work better than thick powder coats for through-coating marking. Specify masking of marking areas in your coating drawings using standard masking tape or fixtures during coating application.
Coating adhesion may be reduced in laser-marked areas due to surface texture changes. For critical applications, reserve uncoated marking zones or apply thin coating layers where marking is planned.
Quick Decision by Coating Type:
- ✅ Thin spray paint → Mark through coating (higher power)
- ✅ Anodizing → Mark before coating (expect color change)
- ❌ Powder coating → Mark before or mask areas
- ❌ Plating → Mark before coating only
Design Takeaway: Call out “mask for marking” in coating drawings with specific area dimensions. This prevents quality issues and ensures coating adhesion around marked areas.
How much does laser marking add to cost and lead time?
$2-8 per part for basic marking, $15-25 for complex graphics, with 1-2 additional days for standard text marking. Complex graphics, multiple marking locations, or difficult materials like PP can increase cost to $15-25 per part and extend lead time to 3-5 days.
Setup drives most of the cost impact. Simple serial numbers or part codes on easily accessible surfaces add minimal cost to existing CNC operations. Marking on multiple faces requires additional setups at $50-100 per setup, plus increased handling time. Volume significantly affects unit cost – quantities below 25 pieces often carry higher per-part costs due to setup amortization.
Material significantly affects pricing. Standard ABS and PC marking uses existing equipment with minimal cost impact. UV laser marking for PP/PE materials costs 50-100% more due to specialized equipment and slower processing speeds. Rush orders add 25-50% cost premium and may require weekend or overtime scheduling.
Compared to alternatives: laser marking costs 2-3x more than labels but 30-50% less than pad printing for small quantities. Hidden costs include programming time ($25-75) and first-article inspection ($50-100) for complex marking layouts.
Cost by Volume and Complexity:
- 1-25 parts, simple text → $8-15 per part
- 25-100 parts, simple text → $3-8 per part
- 100+ parts, simple text → $2-5 per part
- Any volume, complex graphics → Add $5-15 per part
Design Takeaway: Include marking requirements in initial RFQ for accurate pricing. Quantities above 100 pieces dramatically reduce per-part costs, while rush orders significantly increase them.
What should I specify in my drawings to get laser marking done right?
Include marking location, text size, contrast requirements, and surface finish specifications using standard drawing symbols. Clear callouts prevent assumptions and ensure consistent results across different vendors and production runs.
Use standard surface texture symbol with “LASER MARK” note and create a detail view showing exact text layout. Essential callouts include marking envelope dimensions, position tolerances (±0.5mm typical), and reference datums. Specify exact text content and character height. For variable text like serial numbers, use format: “S/N: XXXXXX (6 digits)” to clearly indicate variable content length.
Specify surface finish requirements when smooth finish is required for quality. Include marking depth limits for thin walls: “Marking depth ≤0.05mm max” prevents structural issues. Position marking relative to machined features using GD&T, not approximate dimensions.
For multiple marking locations, create separate detail views for each face with clear orientation callouts. Handle marking changes through drawing revisions – don’t rely on verbal instructions that can cause production errors. Include marking in your initial RFQ package for accurate pricing and scheduling.
Quick Decision:
- ✅ Simple text, single location → Basic drawing callout sufficient
- ✅ Variable content (serial numbers) → Use format “XXXXXX (6 digits)”
- ❌ Multiple faces → Create separate detail views
- ❌ Complex graphics → Include actual artwork files
Essential Drawing Elements:
- Standard marking symbol with “LASER MARK” callout
- Variable text format: “P/N: XXXXX-XX (7 digits + 2 letters)”
- Position tolerances from machined datums
- Separate detail views for multiple locations
Design Takeaway: Treat laser marking like any other machined feature with complete specifications and tolerances. Use standard drawing symbols and variable text formats to prevent miscommunication during production.
Conclusion
Most thermoplastics can be laser marked successfully with proper material selection and process planning. Choose dark ABS or PC for optimal contrast, specify marking locations early in design, and include complete drawing callouts to ensure quality results. Contact us to explore laser marking solutions tailored to your plastic component requirements.
Frequently Asked Questions
Yes, we can mark parts in assembled state if marking areas are accessible. However, this may require custom fixturing and adds setup cost. For best results and cost efficiency, plan marking during your normal machining operations before assembly when possible.
We’ll provide marked samples using your material and text specifications before production. For critical applications like barcodes, we test scan-ability with standard equipment. Minimum readable sizes vary by material – we recommend 0.8mm character height for production reliability.
No minimum quantity for laser marking services. However, quantities below 25 pieces carry higher per-part costs due to setup amortization. We often recommend combining marking with other machining operations to optimize cost and scheduling efficiency.
Often yes, which saves handling time and maintains accuracy. We’ll review your fixture design to ensure laser accessibility. This approach works best when marking areas are positioned away from clamps and don’t require part reorientation for optimal laser access.
Yes, we provide marked samples on your actual material for approval before production. This includes verification of text size, contrast, and positioning. Sample cost is typically credited toward your production order once approved and helps prevent costly marking issues in production.
We provide marking samples for approval before production and guarantee readability according to your specifications. If marking fails to meet approved standards due to our process, we’ll rework at no charge. However, design changes after approval may incur additional costs for setup and programming.
