Take one or more photographs of the image that you plan to print onto glass. Use a 35 mm camera loaded with 35 mm black-and-white film for taking the photographs. As for the speed of the film, you can adjust it anywhere between ISO 100 to ISO 800.
Determine the size and type of glass you will be using. Purchase a piece of glass according to the decided photograph dimensions. Moreover, the glass you use should be of fairly high quality.
Remove any dirt or dust specks accumulated on the surface of the glass. Use quality glass cleaner and paper towel for this purpose. Ensure that the glass is properly cleaned before moving on to the next step.
You now need to add texture to the glass surface. Use a liquid called matte medium for this purpose. Apply a thin coat of matte medium liquid to the glass surface and allow at least thirty minutes for the liquid to dry completely. The texture created by the matte medium liquid will make it easier for the film emulsion to bond to the glass surface.
With touching the matte coated glass surface, place the glass on a flat surface in a darkroom. Apply a thin layer of photo emulsion liquid on the to-be-printed side of the glass. The photo emulsion coat will serve as the printing screen. Allow at least 15 minutes for the photo emulsion coat to dry completely.
Following the exact process that you would have used to print onto photographic paper, print the desired black and white photograph onto the piece of glass. You will need to use darkroom's enlarger, contact printer and other necessary equipment for this purpose. You will have to spend more time at developing the photograph on a piece of glass than developing the same photograph on photographic paper. This is because glass is a lot thicker than paper.