I was at the Army Navy surplus store, and came across some bags I thought could be repurposed for bike use. After some research I found out they're Swiss Army Bread Bags from WWII. They have two leather belt loop straps that conveniently fit over handlebars. They're not much to look at from the front, as most of the leather ends up on the "back" of the bag. They are built super tough, bomb proof dare I say... The canvas over cover is probably close to a quarter inch thick, and holds it's shape. I also found while trying to wash it that the cover is water resistant. The leather straps are super beefy too, and the top one that the belt loops are stitched to is doubled, and gives the bag structure. I paid $14.00 but have seen them online for cheaper.
I set this one to use as a handlebar bag, but with a little modification you could easily use them as panniers too.
I have had a pair of those for a few years and occasionally use them as panniers, with no modifications. Think I got the pair on eBay for about $25, if my memory isn't failing me. The top two straps go on the top rails, and with my Jandd rack the bottom closure will fit on the bottom rail (I've got the Jandd Expedition). Haven't tried it on my other bikes/racks but I imagine it'll work there as well. I just loosely knot the shoulder straps together on top of the rack. The outer cover is pretty water resistant, but the thinner canvas on the back (facing the wheels) is not.
They're also the only bags I've used as panniers that I've had passers by comment on and ask where I got them - for whatever that's worth. Has happened a few times.
AllCity Nature Boy, On-one Pompino, Fuji Roubaix road bike, Orbea Alma 29er MTB, Voodoo Hoodoo converted 69er ss mtb, 03 Gary Fisher Wahoo
Check out the frankenbag....reinforced with canvas, heavy duty stiching, and complemented with a sewn on cross-strap, stabilizer strap, and a cut out from an old reflective vest . best bike bad ever! I sewed this by hand...first time sewing. Has held up for 3 years of abuse.