psd files

I just discovered that psd files (Photoshop something file) can serve as a common file format for different painting softwares. Also there is a small bug in oC (openCanvas) that bothers me a lot. When one select large-sized pencil tool with pressure detection corresponding to pencil size, the sampling rate in oC is not high enough. So at some places the stroke will decompose into a series of small circles, which is kind of annoying. I certainly don't want my hair to be strands of circles. Which means that I'll stick with SAI for a while and save a psd file as a backup in case the development stopped.