Putty, window glazing

In older homes (those constructed early in this century and before), not only were the walls, trim, and other wood components painted with lead-based paint, but almost all metals were primed with red lead or painted with lead-based paint. Lead may be present in milk-based (casein) and water-based paints (distemper and calcimines). It may also be contained in varnishes, which used lead acetate as a drying agent, as well as in window glazing putty.4... 

Glazing compound n. A dough-like material consisting of pigment and vehicle, used for sealing window glass in frames. It differs from putty in that it retains its plasticity for an extended period. Weismantal GF (1981) Paint handbook. McGraw-Hill Inc., New York. 

Glazing - Linseed oil based putties were extensively used in the past for glazing applications. Newer glazing sealants include polysulfide, silieone, and acrylic emulsion. Butyl tape, polysulfide and silicone sealants are used in the manufacture of insulated glass. Safety glass door and window panels ean be made by sandwiching a layer of polyvinyl butyral film between two layers of glass. 

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