Tulle cannot be marked like normal fabric, so I use a different method when cutting tulle. Measure the difference between the tulle and the fashion fabric and write the measurement down. The first thing I do is mark and cut the fashion fabric (outer fabric). For gowns I always chalk the gown, or pin all the way around to ensure I have it straight.
Once the outer fabric is cut, place the garment on a hanger. The hanger I use has a metal swivel hook at the top. Secure the shoulders to the hanger to ensure it “hangs” correctly. Use clothes pegs if necessary.
Hang the gown in a doorway securing it to the top of the door. The door should be open. Sit on a chair or stool, and cut the first layer of tulle to the SAME LEVEL as the outer fabric. If there are multiple layers, cut them one at a time, using the existing cut length of the gown at your guide.
The next step I find easier to do on a workbench, however you may find it easier with the garment still hanging. The tulle needs to be cut a second time to the difference it was originally. Allow for the hem allowance of the outer because at the moment it is still not stitched.
Lay your tape measure over the tulle at the bottom the amount you have to cut and slowly work around the tulle measuring and cutting as you go.
Judith aka genie