I am putting together a web banner that is 728x90. my assets include up to 9 layers. every time i optimize for web, each layer makes the flash file to big. this the first time i am making a web banner. the limit to the .fla file is 40kb. everything i try doesn't seem to work. i've tried converting everything to vectors, and tested with lowest quality possible. my best effort made a 45 kb file, and i hadn't finish importing all the assets. Does everything have to be created in flash in order for the file to be the smallest, or there is a way of importing elements from illustrator or photoshop, and still have it at 40 kb
Any gradients and vectors should be created directly in Flash, or in Illustrator and then imported / pasted into Flash; whatever suits you. I am not sure about copy / paste vectors from Photoshop; but if you have Illustrator - why???
This is the only way to keep the filesize down to your target. Photoshop can only export bitmapped formats, where every single pixel will have its unique colour value stored in the file. Compression will reduce the file size only where there's areas of similar colour. In a typical gradient, every pixels is ever so 'unique' and file size will inflate. Too hard compression will add ugly artefacts. As you probably know, vectors and gradients in Flash & Illustrator use a mathematical description of its content, and can store the information needed for an entire gradient in the same amount of space as say four pixels in a bitmap file.
When / if you need 'photograpic' content, you can make that part in Photoshop, and overlay it on top of gradients ect. in Flash, by using the PNG format from Photoshop, which supports anti aliased / feathered edges on an alpha channel (transparent background).
Not everything that can be counted counts, and not everything that counts can be counted.