A couple of you guys asked this the other day and I was planning on doing some extravagant piece but I think something short and sweet will suffice.
The question was, "How do I paint the purple on the Marines?"
It's simple really. This could go for just about any color really, in fact, I used the same approach as when I paint the red on my Saim-Hann.
The new GW washes have made this process even easier for me since I had to make my own before actually giving in and buying a set of them.
Here it is in a nutshell:
1. Prime with black
2. Basecoat with color of choice (purple)
3. Add wash
4. Apply highlight if desired
Here it is in depth:
1. Prime with black
I prefer spray primers when I'm painting a bunch of guys at a time but I'll brush prime my individual models. I made sure to find a black spray that matches my black brush paint exactly so both can be used interchangeably. I don't have to worry about the two blacks being different when I use them on the same model.
2. Basecoat with color of choice.
The real trick with this part is to find a base color that is opaque.
That way you only have to paint it once. The more layers you do, the more likely you're going to start obscuring details and the longer it's going to take to paint each model. For this project, the original color on the model sent to me by my client used a "mixed" color made from 2 other colors. Virtually impossible to duplicate on a mass scale. I had to do a ton of searching to find an exact match and have it be opaque as well. I ended up getting a near perfect match in a semi-opaque purple so it saved me tons of time and mixing.
3. Add wash.
For this project, I used Leviathan Purple for my shadows. On the picture above, the orange lines represent where it was applied. I didn't paint it all over the purple areas, just in the recesses.
4. Apply highlight if desired.
The real trick with this part is to find a highlight color that is transparent.
Again, just like had to hunt for the purple, I had to hunt for a color to use as the highlight. I lucked out with this one as well and found a near pefect match in a transparent color. The reason I like a transparent color here is that it makes it much easier to blend it into the existing base color. The highlights were added where the green lines are in the picture above.
When doing it like this, you need to start painting your highlight where it is the brightest and let it "fade" away. For example, his left hand... I start at the tips of the fingers and pull my brush stroke downward so that by the time I'm at the end of his finger, I'm just about out of paint and with it being a transparent color, the blend is perfect.
Simple as that, no fancy tricks or anything else.
UPDATE: Since this post is older, I decided to go back and add a few more links to it in order to expand on some of the topics covered here.
How I prime my models
The difference a wash can make
Line highlighting made simple
My Project Link: Space Marines Commision
Additional related links:
Black: Painting and highlighting
Red: Painting and washing