There have been a few questions about unsharp masking in this forum. For what it 's worth, I have been trying masking for a while now and I really like the effec ts. The internal or local contrast is enhanced while not killing the overall con trast. I expose film at high elevations like Bodie Ghost Town at 9000 ft. and th e eastern sierra, and the contrast is sometimes horrendous. Contrast and unsharp masking brings the negative within range of the paper. It works on the highligh ts without flattening out all the overall contrast. I use T-Max 100 or Plus X fo r my masks. I use it on 4x5 and up. You will need some frosted drafting acetate from a drafting supply or art store. I use .005" and .007" acetate. You will als o need a heavy piece of glass like you use when doing contact prints. Raise the enlarger all the way up and stop down your lense all the way. You will want a ne gative that is very diffuse. You want a negative mask that shows very diffuse de nsity in the highlight areas, even less density in the mid tones and no density at all in the shadows. Only zones 6 and up do you want any density. I stack both pieces of film emulsion side up with the drafting film in between. I have cut t he drafting film to the exact size of the film I'm using. I even the film and ac etate edges together and then lay them down as carefully as possible on my baseb oard. When I lay the film stack down I run my finger over the top of the film st ack lightly to push out any air trapped between the stack. I then lay the glass down carefully so that I don't move the film stack. It is very, VERY important t o make sure that the film stack is not moved. If it is moved at all it makes rea ligning the mask and negative that much harder later on. Exposure on my setup is about 3 seconds at f45. I use HC110 at a dilution of 1:20 stock to water at 70* f. After drying I realign the two negatives with each other using my light box a nd a magnifying glass, taping the edges together. The edges of the film base+fog areas is where I try to make the match. There after I always print the sandwich together. The results are well worth the effort. It sounds complicated but is v ery easy. Do one and you will use it often. Condit Manufacturing makes a registr ation system that is not too expensive. Try it and Let me know of any success or failures. E-mail me and I might be able to clear any questions up. If you can, take a workshop from Howard Bond. His workshops are inexpensive and a lot of fun .