I have seen them at places like Staples. I use them for my paper packs. (The ones they sell at Hobby lobby that come with stickers and paper that coordinate). The ones that slant, the wire ones- I get off Craigslist from stores that are closed or closing. Those, I use for solid card stock colors. GL!
I do think they're better for plain paper than for patterned, because (just like at a lot of LSS's) I have to pull the paper all the way out to see what it is and there's too much opportunity to bend the corners, especially with the wire ones. Probably just me but that's what happens. I don't like trays much - I prefer vertical storage a la Cropper Hopper - you can store a lot more paper in less space, and it's easier for me to thumb through and find something without damaging the paper. Again - probably just me!
Kuzatab, that makes sense. I hadn't thought of why storing patterened paper in a tray could be a problem.
I store my patterned paper in my top tray (I have the lipless paper trays). When I need a piece of pp, I have to pull out everything and sort through it to find what I want. But, this kind of works for me. I store the pp in my top tray, and when it's full, I stop buying more pp. It forces me to use what I have on hand. If I'm using pp for a particular project, then I store it in an Art Bin.