Blacking up for diode lasers (and IR)?

I’ve been using nail varnish to black up glass, ceramics etc. etc. but I’m looking for something quick and easy, readily removable OK for most materials. Any ideas please?

Is there anything needed for IR lasers? Are there materials that it cannot cut, because of their colour?

For IR (assuming you mean CO2-wavelength) “color” doesn’t mean anything, because that’s the response to light in the visible spectrum, which CO2 lasers aren’t. Clear acrylic, for example, is transparent to light in the visual range, but opaque to CO2 laser light.

Thanks Oz, yes sorry about my wording. I guess I meant to say are there any materials which are transparent to CO2 and might need covering in order to cut?

I’m not aware of any, myself.