Laser rubber is designed for the laser: it carves cleanly in depth, letting you make a complete rubber stamp in a single operation. It is also the smelliest material there is.
Settings: what really matters
You engrave in negative and mirrored: the areas around the artwork are removed. Remember to flip the design before running — that mistake is a classic.
Depth matters more than contrast: about 1 mm of relief is needed for the stamp to print cleanly without ink bleeding. Achieve it with a high-power engrave in one or two passes rather than many light ones.
A slightly tapered wall lasts better than a vertical one: that is what a deep single-pass engrave naturally produces, as long as you do not slow down too much.
Risks and finishing
The smell is extremely strong and lingering, and the smoke carries greasy soot. Use only rubber sold as "laser rubber" (sulphur-free, chlorine-free) with effective extraction — and warn the people around you before starting.
Soot settles everywhere inside the machine: clean the lens and bed right afterwards.
Wash the stamp with soapy water and a toothbrush to clear soot from the recesses, otherwise the first prints will be grey.
Every figure on LaserSettings comes with the machine, the laser source, the material and the thickness it was tested on. A setting published for a 10 W diode says nothing about a 40 W CO2, and a setting for 3 mm says nothing about 6 mm: check those four things before you copy any number.
Settings are confirmed or disputed by the members who reproduce them, so reliability comes from cross-checking rather than popularity. Photos of the result — cut edges, engraving shades, scorching — tell you more than a single number found on a forum.
Whatever the material, treat a published setting as a starting point: run a small power/speed test grid on an offcut, clean the lens, redo the focus, work with fume extraction and air assist, wear glasses rated for your wavelength and never leave the machine unattended.