I tried to make a perfect embossed rounded rectangle, and then set the background to transparent. I will use this as my application background. But, I always get some unwanted "dirty" pixels in the corner. And it made the rounded corner not good. I use PhotoShop: - Create new WHITE canvas - Create new layer - Create rounded brown rectangle (10 px radius), antialiased. - Apply embossed effect (3 px) - Save it as 24 bit BMP In my application form, I set WHITE as transparent color. This will give my application a rounded look, but I saw a dirty white pixels in the corner. How to avoid this effect? Or should I edited manually (deleting those unwanted pixels using Paint.exe)? I am wondering what do you expert usually do for this kind of task. Thanks, Regards, James

The problem is that you are not using an alpha layer (think, soft shadows, like the mouse cursor in Windows 2000, or WinAmp 5.0)
You should first try to figure out how you can use such a thing programming wise (cos I've no idea, I know about round edges, but alpha layer?)
then u can use the traditional techniques to do alpha layer in Photoshop to get your thing right.

The problem with "dirty pixels" cant be avoided, sadly. All you can do is minimize it by using, say, the most dominant colour you expect your window to sit on as a background layer:
use a red background, if your window sits on a red desktop, but then you'll have red dirty pixels on any non-red background...
if you start doing the thinking, you'll realise that you need an "average" colour of all possible backgrounds, and that's 50% gray.

I remember a sprite artist here a few years back who had the same problem for his sprites in a game, and who got satisfactory results after following my advice.
Maybe it'll work for you too?

Otherwise if you figure out how to use alpha layer (when programming a GUI), then come back and ask again, and I shall tell you how to use an alpha channel (or do a search on this forum, cos we answered that _many_ times before)

Hope this helps :)