An further option to produce a negative for alternative printing is the cliché verre. This art form was “en vogue” at the Barbizon School, notably Jean-Baptiste-Camille Corot and Charles-François Daubigny. Cliché verre dates back to Fox Talbot. Later to Barbizon interest was lost in this technique which is midway to printmaking and photography. The reason here for are explained extensively in this article by Thomas Ketelsen. A sketch of the history of cliché verre may be found over here.
The process to create a cliché verre is quite simple: a supporting material is covered with an opaque medium into witch the the drawing is scratched, drawn or whatever you can do to modify the opacity of the plate. One of the very first techniques consisted to smoke a glass plate with a candle (here a petroleum lamp).
The soot covered glass is scratched with a needle to draw in white lines. The negative obtained this way is used to expose light sensitive paper.
An alternative to this would be to cover the glass plate (could as well be some other transparent support like perspex, frosted Mylar, overhead transparency) with opaque medium: gouache, oil paint, indian ink, … and draw into this like in the soot, press an object into the still wet medium or proceed like for material printing.
The base material should present some grip so that the paint can adhere to the support.
dandelions covered with gouache on perspex:
Note that oil paint needs a lot of time to dry, so I would not advise to use oil paint. Instead use some water based medium.
A painting medium allows for nuances to play with.
Or a craquelure effect (uneven drying, this might be a problem) :