what is the best format for iphone graphic assets.

im working on graphics for an iphone game. I made extra versions of them for all the devises. I gave them to the programer in psd format, witch blew the project way up in size! from 4mb to around 50. I tried png a while ago on another project we did but they looked horrible in the build.

is there something the programer could be doing wrong, something to do with downsampling in unity?

and what would be the optimal format for graphics, its a 2d game btw...

thanks r.

The original format is irrelevant. .psd, .png, .jpg, etc. make no difference whatsoever. The only thing that matters as far as file size goes is what you have as the texture settings in Unity. For example, uncompressed RGBA32 will take up far more space than PVRTC 2 bit, but will look perfect. Therefore you might as well use .psd, so you can keep the layers and so on, and just save the files in Photoshop instead of exporting. For 2D graphics you can turn off mip maps and save 33%, however 2D graphics usually don't look so good with PVRTC compression. 16-bit usually works well, aside from smooth gradients.