A lot of people find that when they save an image from Second Life® and open it in their graphic program, the Transparency seems to be missing. The image is totally opaque.
Yes, it is; but the transparency information is still there, intact. It's just in the Alpha Channel. Watch the movie to find out how easy it is to put it back in the image!
To save an image from Second Life, find it in your inventory, and double click on it to open it in a new window. Then click the Save As button (or the equivalent in your client.)
That opens a browser, so you can save it to your desktop, using whatever name you want.
When you open it in your graphics application, it will be opaque. However, the transparency information is in the Alpha Channel.
So, in Photoshop, hold down the Option key (alt on a PC) and double click on the locked Background layer to float it. (The Option/alt key suppresses a dialog that allows you to name the new layer. If you want to see it, just don't use the key!) Now it's possible to delete part of the layer, so it will be transparent.
Then go to Select > Load Selection. That will open a dialog that lets you choose what Channel to load as a selection. Choose the Alpha channel.
Click the Invert checkbox, so the part that is selected is the background (black in the channel) not the foreground (white in the channel.)
Click OK to close the dialog, and you'll see the marching ants that let you know you have a selection.
Then just tap the Delete key (backspace on a PC) and your transparency will be in the image once again!
Use Command D (ctrl D on a PC) to drop the selection, and you're ready to work.
Remember, if you change the transparency in the image, you need to make a new alpha channel before you can take it back to SL as a 32 bit .tga. When you do, make sure that you replace the old Alpha 1 channel. Otherwise, you'll have what appears to be an opaque image with alpha sorting issues in world.
It's like The Highlander. There can be only one!