I was impressed with this frit company, Reimbold & Strick. Their frit data was educational, by studying the insight-live.com/glossary/118">chemistry of their matte frits, for example, you could see the various mechanisms that produce the effect. But, it is no longer available. However, with a little determination you could likely find the pages at the internet archive (see link below).
Pages that reference this post in the Digitalfire Reference Library:
Frit A 2120, Frit A 3021, Frit A 3032, Reimbold & Strick, The Internet Archive
This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.