My 2 cats & 3 dogs are forbidden from my sewing room but they sneak in there sometimes if the gate gets left open, and I know hair floats around in the air and migrates in there too. My stuff is not sold, just given away but I still try very hard to keep the pet hair off of things because it drives ME crazy to see cat/dog/my hair on things I'm giving away.
Everything is washed after I'm done making it and then if it's something I'm not keeping it goes straight from the dryer into a plastic bag (after being examined for any lingering stray threads, etc), which then goes up into the closet until its time to be given away (never more than 2-3 months, so I'm OK with it being in plastic that long). Or if it's just a couple weeks wait, I'll go ahead & stick the bag in my car (which is a pet-free zone).