These religious icons happen to be on the rear of a pair of suspenders constructed of bicycle chains.
All of the figures are free-hand glass engraving (carving using a diamond engraving tool).
I feel that hand engraving is much more personal than chemical etching of glass. In addition, I do not wish to have the dangerous chemicals in my work area.
Glass engraving has had a very long history dating back to the Renaissance.
The only concession that I made with technology is that the diamond tool is rotated by a hand-held rotation tool. However the movement of the diamond tip is by hand.