jetbunny wrote:I'm looking for a way to make one color (white) transparent in a layer. Is this possible?
If I understand you, you want something like the following procedure:
Make sure you have only that layer visible. (If other layers are visible, they will screw this process up.)
Use the eyedropper to get the color you want transparent.
Go to Select->Color Range. This will select only that color in your layer. (It will select that color in all layers, actually, which is why you wanted any other layers hidden.)
Adjust the 'fuzziness' slider to your liking. If you make it a high number, it will select colors that are similar to the target color. A low number will only select the target color, but could leave jaggies (pixelation).
Hit 'Ok' on the Color Range tool.
Now you have that color selected in your layer. You can do anything you want with it -- it is in your command.
If you want it to disappear entirely, just hit Delete and it will be erased. Note that if you used a fuzzy selection, it will partially erase some other colors, making them partially transparent.
If you want to do other things to it, bring it into its own layer. Cut (Ctrl+X) and Paste (Ctrl+V) it into a new layer. You may have to use the nudge tool to move it back into its proper position. Now you can adjust the transparency of the new layer, or do anything else you like to it. (Filters, screentones, brightness/hue/contrast adjustments, etc.)
If you're trying to save a picture with transparent bits, just make sure those bits are transparent in photoshop and save it as a GIF with the 'Transparency' checkbox selected. GIFs and I think PNGs are the only formats that support transparency -- TIFFs and JPGs do not.
