How to "hide" files from interface builder?

My project uses a huuuge number of png file, all added as resources to the XCode Project. Now, the problem is, whenever I try to use Interface Builder, it parses all these files, and gets terribly slow.

Is there a way to differentiate between resource files that will be 开发者_Go百科used/read by code, and the one that will be used in IB?

I'm not positive, but I think IB only recognizes graphics in the root of the bundle. I think if you put the graphics in a folder and only add the folder (select the "Create Folder References" radio button) to Xcode (so it shows up blue instead of yellow), IB will ignore them. Of course you will also have to specify the new path in the code to use them.