Typically, patterns on glass are applied with paint, sparkles or metal spraying. But the filings are no worse - as the author of Instructables decided under the nickname al3may.
In addition to sawdust (which is full in any carpentry workshop) and glass objects on which you need to get a pattern, the master takes a sieve, electrical tape, an inexpensive brush that is not a pity, as well as such glue that is suitable for wood and glass (PVA does not Suitable, because for glass it comes off).
The master degreases the surface of the glass. He makes a “stencil” of electrical tape, gluing them with glass where there should not be sawdust.
Sifts the sawdust through a sieve to remove large pieces of wood from them. Mixes the sifted sawdust with glue, applies to glass. Waits for the glue to dry completely, after which it peels off the electrical tape. Blows glass to remove non-sticky sawdust. It turns out like this:
Covers everything with clear varnish:
Of course, cups, glasses, and the like, on which the patterns are applied by the proposed method, are no longer suitable for food applications. The method is also suitable for applying patterns and drawings with sawdust through stencils to Christmas balls, plastic products, ceramics, etc. Do not use open flame near sawdust.