Canvas Panels vs Stretched Canvas

I tried my best to finish a painting to post today, but it wasn't to be. I'm currently working on three pieces: A 6x6 of a jelly doughnut, a 6x6 cloudy sky landscape, and an 18x24 of Cape Lookout Lighthouse. They're all coming along slowly but surely, so hopefully I'll have something to share tomorrow.

I'm curious as to what surface other artists prefer for their smaller pieces. I know many use hardboard panels, and it's something I tried for about half a year before I got frustrated with them. I just don't think they're for me, but I guess that anyone that uses hardboard panels will have the same issues I face with canvas panels, which I usually prefer to work with over small stretched canvases.

I've had customers complain about the panels because it's hard to find frames for nonstandard sizes, so I try to provide paintings on stretched canvas when I can so it won't be an issue. I also attach a plastic hanger to the back of each panel so it can still be hung on the wall without a frame. I personally have a hard time finding the sizes I like to work with in smaller stretched canvas; I'm partial to 4x4, 5x7, 4x8 and 6x6, and while I can usually find the square sizes the others are hard to track down reliably. Panels are also easier to store and I prefer not only the feel of having a hard backing while working but also not having to extend a painting around the sides, since on a small piece doing so can really alter a carefully planned composition.

Right now I offer a mix of stretched and panels, and I don't know if I should continue that way or if I should just pick one option and stick with it.