It´s always a headache to export a really cool After Effects "plugged-in" animation to swf, we allway want to use a beautiful animation created in AE than using Adobe Flash. It´s annoying how increase the size in those files in AE. To obtain the best results exporting a swf item here are some interesting tricks:
1.- Keep an eye and take note of your AE compiling size settings
2.- Give priority to all your graphics to be Ai files (vectors)
3.- Thi is the real trick: import your vector into AE with the final size, I´ll make myself clear, If your render AE area is 200 x 200 try to export your Ai vector file in that exact size.
4.- Import the vector file, and animate, you´ll notice that the file size decrease considerely than any other png, psd or even eps files.
5.- Export to swf using common settings.
That`s it ! don´t forget to exporting using rastering setting on, so you can get the best AE effects in swf, best of luck!