Are you describing "glue chipping"? It is a technique that uses hide (or rabbit) glue to chip off flakes of glass from a panel leaving a textured pattern. It has been used for making signs and stained glass windows since the early 20th century.
I have attached a bibliography of books, articles and other materials that describe the technique.
If you wish to obtain copies of any of the items on our list, please contact your local library. The Rakow Research Library is a member of the Online Computer Library Center (OCLC); your library can contact us through OCLC or they may mail an Interlibrary Loan form to us. You may request up to five items at a time. We send photocopies of articles and microfiche copies of our books (if they have been microfilmed) through Interlibrary Loan for four weeks use.
I found a number of websites in "Google" using the keywords: glue chipping. The sites included recipes for glue and descriptions of the process.
For example, these articles may be useful:
Jackson, Mike. “Step-by-step: Glue-chipped glass. Recreate this stunning century-old process.” Signcraft, July/Aug. 1997, pp. 72-77. https://www.signcraft.com/libraries/archive-docs/Step-by-Step-Making-a-Glue-Chipped-Glass-Sign.pdf
Kersey, Stephen E. & Chris. “The Fundamentals of Glue Chipping.“ IN: Kersey’s Glass Works, The Resource Center, Tutorial Center: https://web.archive.org/web/20110825051833/https://www.kerseyglass.com/resource-center/articles/article1.asp
Please let me know if I can provide additional information.
