If anyone is going to get into painting these figures there's some important steps/info they'll need before they start. Basic figure painting can be found here in my guide and I have ones on all the techniques you'll be using for them.
http://www.angelfire.com/mech/...intingTips.html
However to summarize:
1. NEVER use enamel paint. It will remain tacky and slowly dissolve soft PVC plastic that the figures are made of releasing toxic fumes over time. This is probably the #1 cause of failed projects. Also avoid paint pens that say enamel or contain tolulene/xyelene/acetone.
2. Acrylic paint from Micheal's/Walmart like Folk Art and Apple Barrel don't stick well to plastic and need primer first. But primer is very hard to find that isn't some sort of enamel and will make a figure sticky to begin with. I use testors Model Master acrylics you can find at Hobby Lobby and Formula P3. Games Workshop paints will rub off unless you paint them over a basecoat of testors or Formual P3. Tamiya Spray Lacquer [For Plastics] is the only kind of spraypaint I've found that doesn't make the figures sticky.
3. Prep your figure by carefully washing it in warm soapy water. Try not to submerge the base and just wash the figure off under the faucet using a soft nail brush and non-moisturizing soap. You can also wipe it down with rubbing alcohol. This prep step removed the silicon oil, mold release, and hand oils that will keep your paint from sticking.
4. Sealing the figure requires either Tamiya clear spray lacquer or a brush-on acrylic sealer. Don't use modge-podge stuff tho, you'll need Games Workshop 'Ardcoat, Testors clear gloss, or a hobby brand. Krylon makes an 'acrylic' spray sealer called Crystal Clear but I haven't used it on these figures yet. It won't make Marvel Legends pvc plastic sticky so it may work. It comes in matte, semigloss, and gloss.
5. You normally don't need to remove the paint that there but in the event of really glossy metallic paint that repels other paint you have two options. Soak the figure upside down in 91% alcohol for a day making sure not to get the base wet. This sometimes softens the factory paint or removes it without harming the figure. CAREFULLY wipe the section down using acetone on a pure white paper towel. You can't let it sit on the figure because Acetone eats away at plastic, tho much slower on PVC. It will eat the hard plastic ABS base quickly. You can also take 3M 800 grit sandpaper and rough up the surface to allow the paint to stick.
hope these tips help!