One of my many failed attempts to migrate my entire Aperture library had me build full size previews and export them. This was to save edited photos since lightroom doesn't see them. I'm not sure if this is the one that did it, but my Aperture library ballooned from 71 GB to 125 GB. Right now it is sitting at 150 GB which is 15% of my 1 TB SSD. I later tried to reduce the preview size but it didn't seem to make much of a difference. Right now my preview settings are half size previews and quality 8. I'm wondering what settings would give good results while previewing/editing but would reduce the size of my library. My pictures directory by (by reference, on an external disk) is ~2 TB with ~110,000 photos. Only 79K of these are in Aperture as I've been adding new shoots to Lightroom.