Rounded corners with drop shadow [saving transparent .gif]

hello, i am trying to take an image from photoshop which is a rounded square bascially with a drop shadow (partly transparent). basically i will put HTML 'inside of' it (kinda like so
[url]http://www.alistapart.com/d/customcorners/step5.html)[/url]. I need to save the transparent image i made as a gif. then slice it up. but i cant even get it to save as a gif correctly. i save it with transparency but it seems to show a white Matte even though i dont have a Matte setting in Save for Web dialog. I beleive it might be because i have blending on 1 layer to get that drop shadow effect, maybe it needs to be converted to another type of layer be4 exporting?. or maybe it might be an export option i forgot abotu although i tried them all?

i'm using photoshop CS.
Thanks if anyone can help. file is attached here if anyone can help
http://forums.devshed.com/photoshop-help-88/rounded-corners-with-drop-shadow-saving-transparent-gif-317353.html

If there only is one place with one background you want to use this image I sugest you do this:
- fill the background in photoshop with the colour of "the background where you want to use it"
- You won't have transparants parts anymore so you now can save as .jpg ; or as .gif without "matte" if you wish...

but gif's can be transparent. why can't Photoshop save it the same way it looks transparent in my workspace.

i could set the background to the color of the webpage but what if the webpage has a gradient background, then i need the corners of my image to be transparent since they will be spotted easily as backgroudn color wont match edge color( like this rounded corner example the corners have to be transparent http://www.alistapart.com/d/customcorners2/step2.3.html ).

Photoshop cannot save semi-transparent images so it needs a matte colour.

Or you can put a coloured layer behind the drop shadow layer.

I think it happened ones that I was suprised because I had a .gif with a transparent background without a matte, but I don't know how I did it. I guess you must make sure the edges of you image or not semi-transparant, but realy transparant. Other options are:
-) Do it as I described above but try simulating the gradient.
-)Use a matte with a coulor that won't be noticed: The color of you image or a color that is like your background...

if you look at the image used for the corners on that ALA examples you'll notice that it DOES in fact have a matte color, it has to because as others have said there's no such thing as semi-transparent pixels in an image.



take your background and gaussian blur it a few times till you get an even tone (drag the color picker over your image and watch the info palette to check). use that value as the matte for your transparent gif and it should work perfectly. and don't forget to turn off your background layer before you save.

chris

Only way your going to get true transparency is to save as a PNG. Which doesn't work in Internet Explorer Suck.0

All other broswers don't have a problem rendering them though...

their 2nd tutorial seems to have to us transparent ends because their background is a gradient ...
http://www.alistapart.com/d/customcorners2/step2.4.html

but the thing whcih i wanted to know was i guess is this drop shadows, i do see they saved it as a png.
http://www.alistapart.com/articles/cssdrop2

i guess gif only has a bit reserved for alpha then and not alpha and png has a multiple for many semi-transparent values? that makes sense if that is the case.

PNGs have an actual alpha channel so you can have varying levels of transparency. it's rare that you'd really need that to solve a problem though as GIF transparency, though imperfect, is capable of handling most things.

chris