I guess I should have posted this earlier… now that we’re into engraving glass. From some previous work I’d done, you can get a different effect on glass simply with the paint you choose to coat the glass with before lasering… flat-white paint (with high TiO2 content) gives BLACK marking while dark paint/backing gives a “frosted”/ablated marking (note the lizards…).
Earlier today in post #259 I shared a portrait using flat-white paint on transparent glass
So, later I did a "frosted’ image using just a dark backing (tempera paint or matt-black works as well) to ablate the image on transparent glass… same 2.3W laser, same speed/power settings as for ceramic, resized image to fit scrap piece of glass. Here I’ve simply placed the glass on a clean piece of cereal-box cardboard (chipboard) and lasered through the glass with a negative image, focused on the chipboard surface…
Glass and backing separated to show lasered images on both…
Glass simply washed in dish water to remove soot and edge-lighted…
Contrasting the two images on appropriate background…
Using the two laser processes together and with careful registration… you can do two-“color” engravings…
Fun stuff!
– David