ComMarker B4 Review: The Entry Point for Serious Metal Engraving

Last updated June 2026

Who the ComMarker B4 Is Built For

The ComMarker B4 (JPT MOPA version) is built for small business owners, jewellers, personalisation businesses, and serious hobbyists who want genuine fiber laser metal engraving capability at an accessible price point — specifically someone who wants to engrave and colour-mark stainless steel, aluminium, gold, silver, brass, and similar metals at production speed with professional results.

Before going further: the B4 line has both a standard Q-switched fiber version and a JPT MOPA version. The machine sold at The Maker's Chest — and the subject of this review — is the JPT M7 MOPA version. MOPA (Master Oscillator Power Amplifier) technology provides adjustable pulse width control that standard Q-switched fiber lasers don't have. That pulse width control is what enables colour engraving on stainless steel. For the full explanation, our MOPA vs standard fiber laser guide covers the technology in detail.

Watch this ComMarker B4 20W review and performance test:

Unboxing and Build Quality

The B4 ships with a comprehensive kit: the laser unit itself, 110×110mm lens, 200×200mm lens, adapter, foot switch, positioner, flash drive (with EZCAD2), rotary axis, ruler, data cable, Allen wrench, 1064nm OD6+ safety goggles, two sample steel plates, two paperboard samples, auxiliary holder, and a materials sample pack.

The inclusion of both lenses and a rotary axis in the base package at $1,499 is notable — competing machines often charge $100–$200 extra for rotary attachments alone. The two-lens configuration (110mm for detail work, 200mm for larger pieces) covers most production scenarios without additional investment.

The B4 weighs 18kg and measures 336×555×635mm. Desktop-sized but substantial — designed to stay on a workbench rather than be moved frequently.

Key Specs Explained

20W JPT Laser Source

The JPT M7 MOPA is the core specification that separates this B4 from cheaper alternatives. JPT is a premium fiber laser manufacturer known specifically for MOPA technology with wider frequency ranges and pulse width control than standard Q-switched sources.

At 20W, the B4 handles all standard metal engraving, marking, and colour oxidation work. The MOPA advantage: adjustable pulse width (typically 2–500ns range on JPT M7) means you can dial in the heat delivery profile per material. For colour engraving on stainless steel, different colours require different pulse widths — shorter pulses create blue/green, longer pulses create gold/orange — and MOPA control makes this accessible.

Working Area: 110mm and 200mm Lenses

110×110mm lens: Smaller field, smaller focused spot, higher effective resolution for detail work. Best for jewellery, small tags, small text, intricate patterns.

200×200mm lens: Larger field for bigger plaques, larger tumblers, wide logos, and pieces that don't fit in the 110mm window. Lens swapping takes approximately 5–10 minutes.

Electric Z-Axis and Foot Switch

The B4 features electric motorised Z-axis focus adjustment — a meaningful convenience over manual crank machines, improving repeatability between pieces. The included foot switch enables hands-free triggering — both hands can hold or position the workpiece while the foot fires the engraving job, which is particularly useful during high-volume rotary work.

LightBurn and EZCAD Compatibility

The B4 supports both EZCAD2 (included on flash drive, Windows) and LightBurn (separate $60 licence, Mac and Windows).

EZCAD2: The industry-standard fiber laser software. More powerful for automation, scripting, serial numbering, and industrial batch marking. Steeper learning curve.

LightBurn: More intuitive visual interface, better for creative businesses coming from design backgrounds. Works on Mac. For small businesses doing creative personalisation: LightBurn licence is worth the $60.

Real-World Performance

Stainless Steel and Aluminum

Stainless steel is where the B4 JPT MOPA genuinely delivers over standard fiber lasers. MOPA pulse width control enables black/dark grey marking, white marking on stainless, and full color annealing (blue, green, gold, orange, and other tones achieved by adjusting pulse width and frequency to control oxidation depth).

On anodized aluminium: MOPA fiber is excellent — it removes the anodized coating cleanly to reveal bare aluminium, creating high-contrast marks. On bare aluminium: black marking is possible, though higher-power MOPA systems (30W+) provide better colour results.

Deep Engraving and 3D Embossing

Beyond surface marking, the B4 20W can perform deep engraving and 3D embossing on metals through multiple passes. At 20W this is slower than 30W or 60W machines, but achievable for production-volume deep marks on stainless, aluminium, and brass. The B4 60W MOPA handles deep engraving substantially faster for businesses where this is a primary revenue service.

Rotary Engraving

The included rotary axis supports ring engraving (jewellery rings with 360° barrel positioning), tumblers and cylindrical vessels, and pens and cylindrical stock. The B4 is compatible with 95% of standard industrial rotary attachments — users can upgrade beyond the included unit. Based on the feedback from real Maker's Chest customers, tumbler personalisation is one of the highest-volume applications for this machine.

What the B4 Does Well

Color engraving on stainless steel. MOPA pulse width control produces the full range of oxidation colors. For jewellers, personalisation businesses, and anyone selling colour-marked metal products, this is the primary competitive advantage over standard fiber machines in this price range.

Production-speed batch marking. 10,000mm/s galvo speed means production runs complete in seconds per piece.

All-metal material versatility. Stainless steel, aluminium, gold, silver, brass, copper, titanium, anodized surfaces — the B4 handles the full range of metals a jewellery or personalisation business works with.

Package value. At $1,499 with two lenses, rotary axis, foot switch, goggles, and sample materials included: among the strongest value in the sub-$2,000 fiber laser category.

Where It Shows Its Limitations

20W is the low end of production deep engraving. Deep engraving and embossing at 20W works but takes more passes and more time than 30W or 60W alternatives.

Not for organic materials. Wood, paper, and cardboard are outside the B4's effective range. The 1064nm wavelength doesn't absorb well in these materials.

Color engraving requires parameter knowledge. MOPA color engraving requires learning the frequency/pulse width/power relationship for each color. Our how to laser engrave metal guide covers the settings framework for getting consistent results.

No enclosed safety lid (open-frame design). Appropriate laser safety eyewear (included — 1064nm OD6+ goggles) is mandatory during operation.

ComMarker B4 vs ComMarker B6: Is It Worth Upgrading?

For the full specification comparison and decision framework, see our ComMarker B4 vs ComMarker B6 guide.

Choose B4 if: Your primary work is standard metal marking, color engraving on stainless and aluminium, jewellery personalisation, and tumbler marking. The package value is hard to beat at $1,499.

Consider B6 if: You need higher power, extended automation capability, or the B6's specific physical features for your workflow.

Who Should Buy the ComMarker B4?

Jewellers and accessories businesses — ring engraving, bracelet marking, colour engraving on precious metal surfaces. The MOPA colour capability and included rotary are specifically matched to this use case.

Tumbler and drinkware personalisation — the most common small business application. The rotary attachment, 10,000mm/s speed, and LightBurn/EZCAD compatibility make the B4 a production tool for this high-demand market.

Custom gift and promotional businesses — engraving corporate gifts, promotional items, branded merchandise, and personalised products in metals.

Small businesses entering fiber laser engraving for the first time who want professional MOPA capability without the $3,000+ investment required for higher-tier alternatives.

Get the ComMarker B4 directly at The Maker's Chest: Buy the ComMarker B4.

Final Verdict

The ComMarker B4 JPT MOPA is one of the strongest value propositions in desktop fiber laser engraving at the sub-$2,000 price point. The JPT M7 MOPA source provides the colour engraving capability that previously required much more expensive machines, and the complete package — two lenses, rotary, foot switch, goggles — is more comprehensive than most competitors at this price.

Its limitations are real: 20W is slower on deep engraving than higher-power alternatives, organic materials need a different machine, and the open-frame design requires proper workspace safety management. For a business whose work is primarily metal marking, personalisation, and colour engraving: these limitations don't affect the core application. For small businesses entering the fiber laser market under $2,000 with a focus on metal personalisation: the B4 JPT MOPA is the most capable starting point available.

Frequently Asked Questions

What is the ComMarker B4 JPT MOPA?

The ComMarker B4 JPT MOPA is a 20W desktop fiber laser engraving machine using a JPT M7 MOPA laser source at 1064nm. MOPA technology provides adjustable pulse width control, enabling colour engraving on stainless steel by controlling oxidation depth. Specifications: 0.01mm engraving accuracy, 10,000mm/s galvo speed, 110×110mm and 200×200mm lens options, electric motorised Z-axis focus, rotary axis included, foot switch included, LightBurn and EZCAD2 compatible. Available at The Maker's Chest.

Can the ComMarker B4 engrave in color on metal?

Yes — the JPT MOPA source enables colour engraving on stainless steel through laser oxidation. Different pulse width and frequency settings produce different oxide colours: blue, green, gold, orange, black, grey, and white are achievable. This requires MOPA technology; standard Q-switched fiber lasers cannot produce this colour range. The B4 MOPA community has documented standard settings that provide a starting point for new users.

What is the difference between the ComMarker B4 and B6?

The B4 is ComMarker's entry-level professional fiber laser with a compact design, motorised Z-axis, and the JPT MOPA source option. The B6 is the step-up model with additional features and higher available wattage. For the full comparison, see our ComMarker B4 vs ComMarker B6 guide.

Is the ComMarker B4 compatible with LightBurn?

Yes. The B4 JPT MOPA supports both LightBurn (separate $60 licence) and EZCAD2 (included on flash drive). LightBurn provides a more intuitive visual interface suited for creative personalisation businesses and runs on both Mac and Windows. EZCAD2 provides more powerful scripting and industrial automation features for batch production and serial marking.

Is the ComMarker B4 good for engraving jewellery?

Yes — jewellery is one of the B4 JPT MOPA's primary applications. The included rotary axis supports ring engraving with 360° barrel positioning. The 110×110mm lens provides the high-resolution detail quality needed for intricate jewellery designs. MOPA colour engraving enables decorative colour marks on silver, gold alloys, and stainless steel jewellery. The 0.01mm accuracy handles fine text and patterns on small surfaces.

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