Lootens 8th Ed. that I have provides a chapter with details and pictures of the process. Chapter 12 on combination printing.
It details a the process of selecting negatives, making the masks, and determining exposure times.
You can find it at your library, or a dollar or two online as a used book. Not sure if there is an electronic copy available. Try google too.
Also, though I haven't gotten to that section yet, in Way beyond Monochrome, Cedar Falls section details masking for selective burning in.
Last edited by Newt_on_Swings; 11-27-2011 at 08:47 PM. Click to view previous post history.