Ok, this is for photoshop. Only versions I can vouche for are CS2 and CS3, although it may work on others. Also, this is for the sig border, although it can be easily adapted for use in avatars.
Ok, create a new file, size 550x120. BG color>transparent.
Ok, first off, select the pen tool. This sin't a pen tool tutorial, so if you don't know how to use it, use your other favorite selection/shape drawing method. Now draw a shape like this:
Now fill it with white. Now, go over to the layers menu, and where it says Fill (under opacity) change it to 5%.
Right Click on this layer, and select 'Blending options'. Apply these two effects, with the settings as shown:
Here is what the gradient on the stroke should look like:
Note: You can adjust the color of the stroke to fit your sig.
Ok, that part is done. This is what it should look like:
Now create a new layer, and draw a shape like this on it:
Fill this layer with white using the paint bucket tool.
Now, go to the blending options for this layer and apply a stroke using these settings:
All done with that layer. This is what we should have so far:
Ok, now for the highlight.
Create a new layer, and draw a shape like this:
Go to Edit>Fill, and use these settings:
There ya go, your aero border is finished.
To use an image, just paste it above the second layer, and below the highlight. Right click on the second layer and click select pixels. Now, go back to your image, and click on the 'Add layer mask' button at the bottom of the layers window. Unlink the image and the mask by clicking on the little chain between them. This hides all parts of the image that are outside of the second layers transparency. Unlinking the image and the mask allows you to move the image around and transform it while maintaining the constraint of the second layer. Sorry if that was a little confusing :confused:
Ok, so that should be everything for the creation. Now when you save your image, save it as a PNG-24. This is a high quality image file, and it also mainatins 100 of the original transparency, meaning it will have the 'Aero' effect no matter where you post it.
Hope all of you enjoyed my little tutorial. Feel free to post any questions you may have.
P.S. Please dont PM me unless you feel it is absolutely necessary.
EDIT: Made a mistake with the filling of the bottom layer. Fixed it now.