3 to 6 parts by volume Glassite 497A microcrystalline silica powder
1 part pure glycerin
Here is a video showing how to make it. In this video I used 3 parts powder to 1 part glycerin.
I started buying the Glassite 497A from Universal Photonics years back but they recently stopped carrying it based on advice from their lawyers. There is too much of a liability with powdered silica products. It can do lung damage. This is why it is important to put it in water or especially an oil, or better yet glycerin. Anyway Even DAC doesn’t have it in the States and refuses to sample me with their replacement so I am going to go back to Unimin. I did a series of experiments with their products once and discovered a comparable replacement for Glassite. Probably at a lot less money. But if you are a really large window cleaning company that covers many States and is currently bidding on several restoration jobs you might be interested in this kind of knowledge. Otherwise it shouldn’t matter too much. I am talking about cost not quality.