I’m using a cheap projector off BangGood on top of a camera tripod. There’s a bit of set-up time every time I want to cut some fabric since I can’t mount it to the ceiling but it’s still way quicker than printing, taping, and cutting pdf patterns!
This cute raccoon brushed French terry was turned into a Tilly and the Buttons Billie Sweater.
To get the right size, it’s a matter of selecting the right layer on the pdf. I usually have to make adjustments due to my waist-hip ratio and I use Inkscape to edit the files. A lot of indie pattern makers have started supporting projector friendly files. In terms of distortion, you always start with a calibration phase where you project a grid (usually in inches) and adjust pdf zoom & project settings (in case of skew) until the grid matches your physical measuring tool (mat, ruler,…). Then it’s a matter of noting down the zoom percentage and opening any pattern pdf at that same percentage. These files often come with a small little grid on the side as well for a quick double check.