Transposing printing onto fused glass bottle
I think fusible decals may give you the results you are looking for. The kind of decals you make yourself. Just scan your image onto your computer and use a printing/photo manipulating program to make the adjustments you want, then print on the special transfer paper. Just make sure you use the right laserjet printer for the job…the toner has to have the right ingredient (iron oxide) to make the print permanent in the glass. (Check the msds sheet for the printers/toners to see if the ingredient is iron oxide, the higher the level of iron oxide the better your results. A micr toner is great for this application.)
Using the photo manipulation program gives you the choice to lighten/darken the images, add photos, enlarge, etc. (If you don’t have access to this type of printer there are glass artists that will do it for you. The transfer paper is available at many glass retailers and online.)
There is more to the process, but a quick description is to print your image on the transfer paper, soak it in water to remove the backer and slide it onto the bottle. Clean up any residue from the transfer, let dry. Fire. Finished. Keep in mind the results of the image will be sepiatone (brownish).
I hope this helps you!