I think you can get Nalgene bottles online. I'll admit that I probably paid a bit more, but I got most of mine at REI in the camping/backpacking section. I use one of the larger 4 oz. bottles for distilled water when I'm traveling, in case I have issues with a pen getting cloggy (I'll just pour out what I need into a paper cup).
Mind you, unless it's upright in a basket, I will put bottles inside ziplock bags, just to be on the safe side, the way I do for sample vials (which make excellent short-term inkwells, BTW -- I have a lot of samples and if I like an ink I will save the original sample vial and refill it from the bottle -- and that way they're already labeled ). I also have bought some clean empty vials for inks that I didn't have a sample of; I find, though, that return address labels (the peel off-stick on kind) don't stick too well, so I have to then put scotch tape around the edges of the label).
Ruth Morrisson aka inkstainedruth
edited for formatting
Edited by inkstainedruth, 02 July 2019 - 20:57.
"It's very nice, but frankly, when I signed that list for a P-51, what I had in mind was a fountain pen."