This is going to be a write up on a technique that I have used a lot to create a semi realistic looking paint job on a 3D print, for this one here I used the Ieyo bust from Thingiverse.
To start this piece was 3D printed on my Wanhao Duplicator I3 at a 0.1mm layer height in a nice bright colour filament (Voltivo Excelfil Signal Orange) which will help later on when we come to sand and prime the part.
For this particular piece I decided to go with Smooth on's XTC-3D which is a 2 part epoxy resin coating for 3D prints, I mixed the two parts and brushed it onto the bust making sure to not fill any small details and to keep and even level coverage. Once the Epoxy has had time to cure (about 3-4 hours) it was time for a few rounds of sanding. The epoxy has filled all of the gaps so now its a case of getting it super smooth and shiny ready for paint, this result is achieved with several passes of sanding with increasingly higher grades of sandpaper finally finishing off with a 1000 grit wet and dry paper.
Next up is the painting, I first gave the whole piece a few coats of grey primer as a base colour for me to build up my skin tone on. This is a long slow process as I chose to use Oil paints to but the results are incredibly realistic compared to painting with acrylics.
The technique is to use washes (highly diluted paint) of the colours you require such as reds, yellows and purples and painting them on, wiping them off and repeating until the desired depth of colour is achieved, it helps to have some reference on hand when doing this to have colours to match against.
The final result is very nice as there isn't a cartoon aspect and keeps the item looking more real and creepy, the same technique can be used on buildings or anything that needs to be subtly painted and not pop with bright colours.