trying to print on 17" by 50' roll on a 7880 with printool

Guess this might be obvious, but not to me. When selecting paper sizes there is 11x14 on a roll and 24x16 on a roll but no size for 17" rolls. Can I just go ahead and print custom sizes on a roll and will it cut off at the right distance or do I need to enter a custom size indicating the roll length?
Any help would be great before I buy a 50’ roll.

Yep. Go ahead and make a custom size.

QTR- should be able to to 50’ but may hit up against RAM limits based on your computer specs. I recommend 16+ GB of ram if you are going over 20’ on a single print.