It is like drawing inside-out, to make a picture in white on a dark background. Basically, everything which should stay dark is a hole and is not drawn.
I really love the effect of laser-engraving in glass mugs. However, this effect is rather subtle and is best seen from a close distance and when the glass is filled with strong coffee or tea. Photographing it, is less easy.
These mugs are produced by Steklarna Hrastnik, a Slovenian glass factory which is known for their high-quality work. They also do the engraving with my drawings.
