DIY Canvas Panels For Oil Painting?

Thank you! That was exactly one of my concerns. Can i ask how long after gluing the panels start warping?

I’ve seen someone (on Youtube, so take it with a grain of salt) paint a big “X” in glue on the backside of the panel. I haven’t tried, but the theory was that it would counter the pull of the shrinking glue on the front and keep the panel flat. I might run an experiment on this, hence my question about how long the warping takes. If it happens quickly then that’s actually great, well, at least better than if it happens weeks or months later after the painting may have been sold.