Modern Vespa

Anyone have any recommendations for good, reasonably priced travel bags for GTS touring? I'm thinking something that'll sit on the pillion and either strap under the seat or to the rear bars. Obviously it'd need to be easy on and off if it didn't lift with the seat (what with stopping to top up every hour and a half). Bonus points if it has some molle straps, because I have a couple of fuel bottles that would then not need to be in the pet carrier or topcase. Been looking around and nothing has struck me as just right yet.

I'm a bit of a packrat when on long journeys - every time something goes wrong I end up with new back-up plan added to my kit. Plus clothing I guess.

Define "touring" as in duration. Days, weeks, months?

If you want MOLLE, I had a military surplus backpack (35L size) that I used with ROK straps. If you use 2 sets of the smallest size, you can set it up as an upright quick-release bag. Top halves of the straps loop into the MOLLE webbing; bottom halves go to either grab bar, crash bars, or rear rack corners. Dealer's choice.

Good point on duration: for me touring caps out at a few days. I'll try the military surplus angle - thanks.

I have the German made T-BAG by SEA ´N´ SAND in daily use. Large capacity and keeps the center of gravity low and forward. See https://www.seansand.de/english/