Some with more experience than I, said she used fabric pens and filled in the "off" places. It works!

I rarely have the outline off anymore.
I use different materials for hooping than most people.
There is a sticky window film that stucco guys use to put on the windows to protect them from getting stucco on them while they are doing the house. I pull off enough to cover the inside part of the hoop, sticky side up. I then take a washable glue stick and outline the inside of the hoop onto sticky film, extra holding power. I lay a piece of material onto the sticky side and hold it for 10 seconds to make sure the glue sticks. I slip another tear away stabilizer under the just before I start the embroidery. I bought a large roll of tear away and cut some of it into 4 inch squares, some into larger for the larger hoops. No waste.
The film sell for 45.00. It's about 20 inches wide and 400 yards long so I will not be running out anytime soon.
Syl