Excerpt from the book Save America's Windows http://www.historichomeworks.com/hhw/reports/reports.htm#Windows Step 9d. Paint. Apply primer to putty bevels and interior seals. Lap primer 1/16" onto the glass, painting "to the line," allow to dry. Apply two top coats of paint to entire sash except side edges and face margins and top and bottom edges if they are not being painted. (Use best quality exterior house paint. Waterborne 100% acrylic paint is good, as is oil-based alkyd resin paint.) Lap paint 1/8" onto to glass. If you can (with practice) lap the paint onto the glass just a bare 1/32" to 1/16", so much the better. Allow paint to dry and cure thoroughly. The over-paint-and-scrape-back method is problematic. Slopping paint onto a wide margin of the glass and then coming back to scrape it off takes more time time than painting to a line. Slow down and learn to paint to a line, you will be saving time after three to five sashes. (Yes, you can learn to do it, I have taught 13 year old kids, and 72 year old grandmothers to do it, by showing them just once.) Join us at the Historic HomeWorks windows discussion forum: http://historichomeworks.com/forum/viewtopic.php?t=955 See the full-length 20 minute video and others in the series: http://www.historichomeworks.com/hhw/video/rftf.htm#Reports Learn how to paint and restore older and historic windows at my workshops and training sessions: http://www.historichomeworks.com/hhw/education/seminars.htm Copyright 2010 John C Leeke Less