A laser cannot engrave PVC or vinyl safely, cannot mark bare aluminum or chrome without a coating, cannot reproduce color, and cannot hold detail below roughly a millimeter. Everything else on this list is a matter of degree. Knowing the limits before you design around them saves everyone a disappointing proof.
I'm Veronica Ramirez, owner of Palm Coast Customs in Estero, Florida. I would rather tell a business what will not work up front than take an order and deliver something underwhelming. Here is the honest list.
Materials I Will Not Cut or Engrave
PVC and vinyl. When a laser heats PVC it releases chlorine gas, which is genuinely hazardous to breathe and corrodes the machine itself. No reputable engraver will run it. If you have a PVC sign or badge you want marked, the answer is a different material or a different process.
Polycarbonate. Discolors badly, yellows at the edges, and produces a poor result even when it does not fail outright. Acrylic is the correct substitute and looks far better.
Anything with an unknown coating. If I do not know what a finish is made of, I will not put a laser to it without testing a sample first. Unknown coatings can release fumes or destroy the finish in ways that cannot be undone.
ABS and many plastics. Tends to melt and discolor rather than mark cleanly.
Materials That Need Something Extra
Bare metal — stainless, aluminum, brass, titanium. A standard CO2 laser cannot mark raw metal directly. There are two workarounds. A marking compound can be applied and fused into the surface, producing a permanent dark mark. Or the metal can be coated — which is exactly why powder-coated tumblers engrave so well, since the laser is removing coating rather than cutting steel.
Chrome and mirror finishes. Reflect the beam. Not workable without a coating or compound.
Glass. Engraves, but differently. The laser fractures the surface into a frosted white finish rather than cutting depth. It looks excellent for wine glasses and barware. It will not produce a deep engraving, and glass with tempering or curvature can be unpredictable.
Very oily or resinous woods. Some tropical hardwoods have resin content that scorches and produces inconsistent contrast. Baltic birch, maple, walnut, and bamboo are reliable.
Design Elements That Do Not Work
Color, of any kind. Worth stating plainly because it surprises people every week. A laser produces one tone. On a coated tumbler that is the metal underneath. On wood it is a burn. There is no way to engrave your brand blue.
Gradients, shadows, and glows. No tonal range exists. Every point is engraved or it is not. A gradient has to be converted into solid shapes, and someone has to decide where the edge falls — a design decision, not a technical one.
Text below about 8pt at final size. Letterforms fill in. Counters — the enclosed spaces in a, e, o — close up, and the word turns into a dark smudge. Taglines under a logo are the most common casualty.
Hairline strokes. Thin outlines and delicate script can vanish entirely against a coating, or break into dashes.
Photographs. Technically possible on some materials as a dithered pattern, and it rarely looks as good as people hope. I generally steer businesses away from it.
Full wraparound designs on curved objects. The laser engraves a flat plane. The further a design extends around a curve, the more the edges distort. Staying in the center third keeps everything crisp.
Sizes and Shapes That Cause Problems
Anything with a deep curve. A steeply tapered glass or a strongly contoured bottle limits the usable engraving area.
Very large items. Bed size is finite. Oversized signs may need to be produced in sections or engraved in multiple passes with realignment, which adds cost and risk.
Items that will not sit flat or rotate evenly. Irregular objects sometimes cannot be held in a stable, repeatable position, and consistent results depend on consistent positioning.
Assembled products. If a piece is already screwed, glued, or upholstered together, it often cannot be positioned correctly. Engraving before assembly is almost always better — worth planning for if you are having something made.
What to Do Instead
Need color? UV printing or vinyl. Different vendor, right process.
Need bare metal marked? A marking compound, or choose a coated blank instead. Coated is usually cheaper and looks better.
Logo too detailed? Use your simplified mark. Most brands have one. If yours does not, simplifying it is worthwhile — you will use it for far more than engraving.
Tagline will not hold? Drop it, or enlarge the whole design. The tagline is the first thing to become illegible and the last thing anyone reads.
Material is PVC? Acrylic for signage, or aluminum with a coating for badges. Both look better anyway.
Why I Would Rather Say No
I turn down work fairly regularly. Someone wants a photo engraved on a curved surface, or a full-color logo on a black tumbler, and the honest answer is that the result will not meet what they are picturing.
Taking that order and delivering something disappointing costs more than the order is worth. The proof stage exists to catch this, but the better time is the first email — before anyone has spent money or time.
If you are not sure whether your idea is workable, describe it or send the artwork. I will tell you plainly whether it will work, and if it will not, what would.