A quite lengthy discussion of the issue (acrylic paint lifting from the surface) has been going on at Painters-Online (www.painters-online.co.uk) but it might help to summarize the main points here.
- Acrylic paint can lift from the surface if it's under-bound, i.e. if it's diluted too much.
- There is a problem with some canvas-boards, canvases and other boards sold as being fit for acrylic painting. This became obvious when I took a close look at a number of boards I've just bought: something has been used - perhaps to inhibit mould growth, perhaps for other reasons - which has given the acrylic gesso a shiny surface which repels water, and will also repel acrylic paint.
- Papers - watercolour paper, mountboard etc - are not affected by this and can be used safely with acrylics.
- If it doubt about a canvas board or canvas, wash it - warm water, plus a very small amount of washing up liquid, scrubbed into the surface (carefully!) with a nail-brush until all the shine is removed. Applying a coat of matt medium (anybody's) will also encourage the paint to stick. And I've found that using Daler-Rowney's acrylic gesso on the surface, over the existing priming, also helps.
- If you buy canvas boards or canvas sold for acrylic use which have a shiny surface, bring it to the attention of your supplier: Manufacturers need to be discouraged from adding anything to acrylic gesso which actually repels paint - whatever made them start doing it, they need to stop!
- Take more than a cursory look at your boards - hold them up to the light: if you can see glittery bits in the weave of the canvas, it needs to be washed. If you spray the surface with water, and notice the water is being resisted in places, again - it needs a wash.