Cleaning of the plate with ammonia before the first adhesive coat :
- In prerequisites, glass plates will have been cleared of the coat of gelatin of the previous edition (see: cleaning of glass plates).
- We begin by cleaning perfectly the surface of the glass with ammonia water to avoid any risk of later unsticking of the gelatin – thing which never has to arrive. For that purpose, wet slightly a cloth microfibers for windows (wet it completely in the cold water, and press it averagely), pour then above a little pure ammonia water of the trade.
- With this cloth soaked with ammonia water, to wipe all the surface of the window as well as its edges. The operation is little pleasant because of the strong smell of the product, but fast and without danger. There is no better means to prepare glass to receive both coats of gelatins which are going to follow (the 1st coat which serves as adhesive – 2nd coat which will constitute the printing matrix).