Prop TransparencyLooking into the invisible regions.
The transparency mask is not preserved when pasting pictures back and forth between programs. My method to deal with this is to place the picture on a flat background color that I'm sure I won't be using in the av picture itself. Usually an extreme green or blue ("bluescreen," heh). The color I usually use is [R51 G255 B0]. This is a color that's already in the Palace CLUT, so Photoshop will never dither it when converting color spaces.
If you edit props in Photoshop a lot, you might want to make yourself a Photoshop swatch file (viewable in the "Swatches" palette) composed exclusively of colors that you know are already present in the Palace's Color Table.
In PS 3.0, I put this flat color in a background layer, and leave the av in a transparent foreground layer with a layer mask, "flattening" only when converting to indexed color. When using older versions (like PS2.5 on my ancient, memory-challenged Mac SE/30), I save the flat region as an extra selection channel, too.
The transparency channel for the Palace is one bit. That
means it's or of it's off. That's not the same as Photoshop, which
allows 256 levels for soft edges (feathering) and other effects. So
you'll have to stomp on that transparency mask use the PS Levels
command to force it. Select only the transparency channel (usually
#4) (or the layer mask), select "Image -> Adjust ->Levels..."
and try typing in the values
127 <tab> 1 <tab> 129
in the "Levels" Dialog Box. The grayscales should pin
to black and white (or the layer-mask edges will be come jaggy).
Once the picture is actually in the Palace Prop Editor, you can easily delete the odd-colored areas with the eraser. Holding down the Control key while erasing will quickly fill-erase large areas of contiguous color.
Copying from the Palace prop editor, the transparent areas will go black. If your prop had black edges, you won't know where they are any more! There are two good solutions for this problem:
Antialiasing Avatar Edges