What are best economy canvas boards?

I sometimes paint on canvas cut from a roll and glue the finished painting to a cradled wood panel. I buy the panels from Art Discount, their own brand. I use Bindex to glue the canvas to the panel but any archival (acid free) pva based glue will work. I roller them together from centre out with a clean brayer and leave to dry a good 24 hours before cutting off the excess canvas with a new blade. I can see no reason not to do the same with paper. I have also used birch ply instead of panels that I had cut from a firm called cut my plastic, really nice, super quality.  I had a bad experience with canvas boards that delaminated. I don't use them at all. 

Canvas boards are problematic - delamination can occur, as Collette says, with certain brands: I've tried to cover this before in various posts, but of course things get buried.  So to repeat - if you do buy one of the "economy" boards, do subject it to a raking light - if you see glittery bits in the weave, it's been treated with something, probably an anti-mould preparation.  Take a nail brush, or any stiff brush, and wash that off - a bit of water on the brush with a touch of vinegar will get rid of it, but check it carefully to ensure all the glitter is gone.  And obviously, allow it to dry thoroughly. Good boards include Belle Arti canvas panels, or Winsor and Newton panels - both resist warping, though I can't unreservedly recommend Belle Arti on that front: I know Alan Bickley uses them and likes them, but I have known them to warp slightly.  Getting them in a frame counteracts that.   I used to use Loxley canvas boards, and Daler Rowneys, but the quality of both has declined.  As you're after economy, Dmitry, I won't mention stretched canvas or really rigid boards.   I'm intending this as a supplement to Collette's reply, just to be clear, not contradicting it in any way.