Painting figures with children
I use artists acrylics because I am painting keepsakes for adults but they are not really suitable for young children to use or paint toys with.
You should look for paints that are child safe - that's not quite as obvious as it sounds, as you're just as likely to find them in the room paints at a DIY store as in a paint box (look for things that are toy safe or EN71-3 certified)
There's a lovely company called Tiny Land that make food grade paints for little ones - if you are looking for bright colours for stains, they'd be a great place to look
The sealer is important too - again, look for toy-safe, ‘low VOC’ sealers. If you use a children's paint many are designed to be soluble (i.e. washable) so it might be worth doing a test figure before sealing, or you may find you are re-hydrating your paint and dragging it off again, but a stain with a sealer looks really lovely. Different sealers suit different paints.
The Brewers paints website give some good guidance about safe paints.
Painting portrait and wedding figures
I tend to use a range of artists and craft acrylic paints. You can use acrylic, gouache or even watercolour, but the more watery the paint, the more it will raise the grain of the wood. For youngsters, even felt pen is effective but it will bleed into the wood grain. When I paint the skin colour I paint a couple of coats, and then sand the figure back, before painting two or three more. It gives a lovely smooth surface for detail, but it takes a lot of coats to paint over it and get a uniform colour – even for a white dress!
The pegs are great fun and can be done with one or two coats of paint, if you don’t mind a slightly rough surface. The colour will go on stronger in earlier coats as the water is absorbed into the wood more easily. You can pencil in your design and paint separate colours between the lines, or paint the whole figure and build up your layers as you go. I tend to do the latter but it is much more time consuming.
Then I use a water based acrylic sealer over the top. The best general purpose one would be a satin finish water-based sealer/varnish, preferably ‘toy safe’.