My daughter's cat ate 1/4 " ribbon the day before we were to leave on vac. She got so sick and we had no idea what was wrong with her. I took her to the vet and she had to stay over night so we had to have a friend pick her up and cover the expense until we got back. She'd eaten about 18" of red ribbon with the lacey stuff along the edge. The vet said it was harder for her to pass because it was rough along the edges which made it easier to catch and strangle her intestines.
Fortunately she didn't need surgery because we couldn't have afforded that. She lived many more years after that but we were extra careful about leaving things like that around.