I've been somewhat troubled by hardboard/Masonite for some time. It's prepared with Linseed Oil, and this is not a great basis for acrylic. Although many commercially available boards for painting in oil or acrylic are based on hardboard. It's hard to research this - you'll find a lot on tempered hardboard, outdoor hardboard, internal hardboard - and none of it really seems to answer the fundamental question a painter must ask: is it safe to work on? Prepared hardboard/Masonite panels are available which declare themselves OK as painting surfaces in oil or acrylic: they've been primed with acrylic "gesso" (a misleading term in itself, because it's not real gesso) - yet if that's suspect as a base, it's as suspect for oils as it is for acrylics. Personal experience isn't very helpful here - I have an acrylic on hardboard, painted in 1991, (also varnished with Matwax), which hasn't changed since I painted it; and an oil on hardboard primed with a lead oil paint - which also hasn't changed in some 25 years. But that doesn't mean to say they won't..... Does anyone out there have a longer experience of hardboard, primed/sized in various ways, than I have? Or technical expertise? All I can get from museums and galleries is that the hardboard-based paintings vary a great deal in their resistance to change and decay; some show no sign of change, others are crumbling and disintegrating. Which, taken as a whole, is as helpful as a swift kick in the nether regions...... Hardboard has the huge advantage of being cheap, and readily available. However, that's not of much help if you're hoping your paintings will outlive you. I haven't used it for a while now - preferring either stretched canvas, or MDF panels (and I just bet someone's come up with 50 reasons why you shouldn't use MDF....... ): I'm wondering if painting on anything other than granite is really such a bright idea..... Any thoughts, though?