Which laser suits slate & granite photo plaques
For natural slate, black granite, a CO₂ laser (10.6 µm) is the usual choice. A CO₂ laser works at a wavelength that organic materials absorb well, including wood, leather, acrylic, paper, cork, fabric and glass. It removes or darkens a thin surface layer to leave a clean engraved mark.
A CO₂ laser does not mark bare metal on its own. Metal needs a fiber laser, or a special marking compound applied before a CO₂ pass.
When a Fiber laser makes sense
A fiber laser works at a wavelength that metals absorb well. It marks stainless steel, brass, aluminium, anodised aluminium and coated metals, and many hard plastics, with a permanent mark and no consumables. For slate & granite photo plaques, consider it if your range includes materials the CO₂ laser does not handle well, or if you need a different finish.
Setting up the job
Slate marks light grey against the dark stone with CO₂. Black granite holds finer detail, and a fiber laser can also mark granite when the portrait needs very fine dots.
What to check before you buy
- Material match. Confirm every material you plan to sell (natural slate, black granite) with a test mark before deciding on the laser source.
- Marking area. Measure the largest design area you will mark. A standard galvo field is often around 100 by 100 mm, and larger lenses give a bigger field with slightly less fine detail.
- Power. For marking and engraving gift items, galvo CO₂ markers commonly run between 30 W and 60 W. If you also need to cut shapes or work on large sheets, look at a flatbed CO₂ machine with a moving gantry, which is a different class of machine.
- Software. Check that the software imports vector files and name lists from a spreadsheet, and handles photo engraving if you plan to offer it.
- Fume extraction. Every laser marking job releases smoke or fine particles. Budget for a proper extractor and ventilation from day one.
- Power supply. Use a voltage stabiliser or online UPS. Unstable supply can damage the laser source and controller.
- Safety. Open galvo markers need protective eyewear rated for the laser's wavelength, or an enclosure. Never laser PVC, vinyl or unknown plastics, because some release corrosive and toxic gas.
Running this work in Chennai
Photo plaques take longer per piece than text jobs, so price them by engraved area and keep finished sample tiles in the shop to show the tone.
Gift shops in Chennai's busy retail streets compete on turnaround, and a customer who can collect a personalised item the same day is less likely to shop elsewhere. Chennai's gifting trade runs through retail markets such as T. Nagar and Parry's, the corporate offices along OMR and Guindy that buy gifts in bulk, and the marriage halls across the city that create return gift orders every muhurtham season.
NMB Enterprises is a laser marking machine distributor in Chennai, based at Poonamallee, so buyers in the city can reach the team directly to discuss their product and the machine that suits it.