From time to time I like to export my ArtRage image to Photoshop and back again, usually to make simple layer transformations (i.e, repositioning elements, scaling, rotation, etc.) One problem I found is that the .ptg filesize will dramatically increase when the image is brought back from a .psd. Here's the solution I've been using:
When I'm working in ArtRage, I'll usually make the bottom most layer a paper-only layer and only draw on layers above it. This leaves me a lot of flexibility for reusing the artwork in different ways after I'm done. What I've found, however, is that Photoshop apparently embeds some extra data in the bottom layer that can unnecessarily increase the size of a .ptg when the image is imported from a .psd. My solution is simply to create new paper layer above the original paper layer, and then delete the old paper layer. When you resave the .ptg, the filesize will go back to it's nice tiny ArtRage size.
BTW, I'm obviously happy that AR2.5 will allow transforming 'cel' layers so I won't have to deal with this for much longer. Hope it's coming out soon!
Thanks guys, and keep up the fantastic work!