My reply is late, but I hope it will still be useful. Alan's procedure is described in detail via a series of articles in View Camera magazine. I have copies and will get the dates for you. I use this procedure regularly for both enlarging and contact printing. It is a wonderful tool. You will need some **translucent** plexiglass. 1/16 inch is best, but 1/8 inch works too. You tape your plexiglass over the glass of the contact frame. I remove the glass from the frame. The negative is taped on the bottom side of the glass, and the plexiglass is on the top side. With Alan's procedure, you don't sandwich the frosted mylar between the negative and the glass. You tape the frosted mylar over the plexiglass, which is taped on top of the glass. By using the translucent plexiglass, the penciling effects go unnoticed because of the diffusion effect of the plexiglass. You do want to be smooth about it, but the plexiglass reduces the need for absolute smoothness in the penciling. There's also no grain effect due to penciling, because the plexiglass removes it. You place the glass on the lighbox and tape the frosted mylar over the plexiglass. At this point you will see a fuzzy image thru the plexi/frosted mylar. You can dodge/burn a tree, rock, whatever, *precisely* by penciling in on the frosted mylar. If you don't like the results, just remove the frosted mylar and start over. How do you burn? Just cut a hole in the frosted mylar the exact shape of the area you want to burn. Use as many sheets of frosted mylar as necessary to get the burn you need. I've also used tracing paper with the frosted mylar when I really need to burn an area in really well. You tape all your frosted mylar sheets/tracing paper sheets together to create a "mask package". When you need to make an identical print, just align the "mask package" with your negative by viewing the fuzzy image via the light box. Alan uses an example in the article where he forgot that his filter causes vigneting. The corners of the print were vignetted. No problem. Just pencil them out! He has a "before and after" image in the article. With this procedure you can burn/dodge as many areas as needed simultaneously. Alan has a list of materials that he uses and where he gets them in the articles.
Part 2 or 3 (I can't recall at the moment) of his articles on Selective Masking describe a procedure in which you scan the negative into the computer. You then use Photoshop to "pencil in" the areas you need to dodge. You print the "mask" on overhead transparency material with yellow ink, to be used with variable contrast paper. This allows you to dodge/burn and control contrast in multiple areas simultaneously. The procedure is too lengthy to describe here, but when I get the View Camera article dates, you can get the articles and read about it in detail.
Eric.
