This is easy =) You have to 'pre-multiply' all masks. Here's what I do:
1. Create the element in Photoshop, utilizing transparency.
2. Merge everything you want visible to a single layer.
3. Create 2 rectangular regions (size determined by the resource you're replacing) - one each for the artwork and its 8-bit mask... fill these with black.
4. Position your artwork layer over its corresponding black region (it's still floating on its own layer).
5. Create an accurate mask selection by command-clicking the artwork layer (thus converting transparency to a selection). Drag your resulting selection with any selection tool to its exact corresponding spot in the rectangular mask region - then fill your mask area with white. You now have 2 aligned regions with black backgrounds - one contains the artwork, the other the mask.
6. Now make sure your mask region is merged (the white mask and its rectangular outer black area merged into a single layer).
7. Duplicate this layer, move it up so that it's above the artwork layer and position it exactly so that it's aligned directly over top. Make this layer's apply mode Multiply.
That's it... as long as everything lines up from artwork to mask and you've multiplied the mask over the artwork you should have no problems.
Hope this helps
Works for me every time no matter what the shape. When I adjust overall transparency for disabled states, I Multiply a solid black fill (at whatever negative transparency over the entire disabled mask, then merge-duplicate-position-Multiply as above... playing with levels or curves on the disabled mask might cause problems if the resulting ramp manipulation isn't linear (but shouldn't make a difference if the resulting mask is multiplied over the artwork).
1. Create the element in Photoshop, utilizing transparency.
2. Merge everything you want visible to a single layer.
3. Create 2 rectangular regions (size determined by the resource you're replacing) - one each for the artwork and its 8-bit mask... fill these with black.
4. Position your artwork layer over its corresponding black region (it's still floating on its own layer).
5. Create an accurate mask selection by command-clicking the artwork layer (thus converting transparency to a selection). Drag your resulting selection with any selection tool to its exact corresponding spot in the rectangular mask region - then fill your mask area with white. You now have 2 aligned regions with black backgrounds - one contains the artwork, the other the mask.
6. Now make sure your mask region is merged (the white mask and its rectangular outer black area merged into a single layer).
7. Duplicate this layer, move it up so that it's above the artwork layer and position it exactly so that it's aligned directly over top. Make this layer's apply mode Multiply.
That's it... as long as everything lines up from artwork to mask and you've multiplied the mask over the artwork you should have no problems.
Hope this helps
Works for me every time no matter what the shape. When I adjust overall transparency for disabled states, I Multiply a solid black fill (at whatever negative transparency over the entire disabled mask, then merge-duplicate-position-Multiply as above... playing with levels or curves on the disabled mask might cause problems if the resulting ramp manipulation isn't linear (but shouldn't make a difference if the resulting mask is multiplied over the artwork).