Space Hulk is almost old news at this point and I hate going over the same stuff someone else already has. Eriochrome's stealing the math-hammer thunder with his excellent articles over here: http://twilight40k.blogspot.com/. There's also a plethora of people showing how they are painting the figs to greater success than I expect to have. I could also rant about the quality miniatures and product, but that's also been done and re-done too.
(Okay, I have to voice a bit of dissent here... The minis are overall quite great, but there were a couple shortcuts taken on details that I don't like. For example, the obvious CAD undercut of the skull on the right knee of the Thunder Hammer guy. Why not just have it oriented correctly? Or the lack of any decent detail or surface on the hips and legs of the Genestealers. Both are minor, but detract enough that I'd only give these models a 9/10.)
But back on topic! I've gotten the opportunity to paint the new Space Hulk figs for my friend Artimese. He's not a good enough painter to match the Genestealers to the rest of his Tyranid force, so he asked me to do them. I can't really call this a commission as that would be pretentious and imply I was getting paid. But he is a good friend and just had a kid, so call it an act of charity? My requirement was that I get to paint the rest of the figs too, as I wanted to try my hand on those Termies.
It wasn't until I got the box home that I realized I'd also be painting the objective markers and doors. It's the latter that I'm here to talk about today, since I haven't seen anyone else talk about them.
To prep the pieces for painting, I first cleaned the flash off with a hobby knife. They were then lightly scrubbed in a little bit of soapy water and rinsed off. Then I basecoated them with a mix of 50% Liquitex Black Gesso, 25% Future Floor Wax, and 25% water.
To me these doorways appear to be made of corrugated steel plates or some futuristic equivalent. Notably, the cardstock doors and floor pieces are mostly Codex Grey with Fortress Grey hightlights. I tried out 4 different test pieces running from a pure metal look (Tin Bitz w Boltgun "wear") all the way to a pure ceramite (no metallic wear). The resounding favorite was the process shown below. You can click on any image to see a larger version.
Step 1: Codex Grey. The first bit of color was to lay down a heavy drybrush of Codex Grey. I wasn't particularly worried about perfect coverage or smooth lines. I knew I'd be putting a good bit of other color down after this step. Plus, these are just terrain pieces. :-p
Step 2: Fortress Grey. This was the most time consuming step. I went and put highlights on all of the pieces using Fortress Grey. Most of the pieces were done using 2-step layering and then edging with pure Fortress Grey. But I wanted some variation in pieces, so some were done with wet blending and others with direction oriented highlighting. (If these terms don't make sense, poke around the intarwebs. Many painters more skilled than I have excellent articles on these techniques.)
Step 3: Boltgun Metal. Many industrial applications use painted steel for decking and walkways. Wear and tear will eventually reveal the steel underneath along the patterns of greatest wear. So Boltgun was applied in a V pattern narrowing as you go into the doorway. Certain edges and wear points were also given some metallic edging or streaking.
Step 4: Dheneb Mud. This step could better be said as "It's too CLEAN for a Space Hulk. Make it dirty!". Every piece was given 2-3 coats of Dheneb Mud, with emphasis to accumulation on flat surfaces on into crevices.
Step 5: Badab Black. This was the final layer of finishing and shading. A single coat of Badab Black was used to darken the crevices, furthest corners and deepest areas of rust and grime. After this, some extra grime was added to the left side of the piece by painting on a mix of Baking Soda and Dheneb Mud. That was an off the cuff experiment that I'm quite happy with.
The final pieces are sealed with a hard gloss coat (Future) and then dulled back to true with a matte lacquer.
If the step by step wasn't enough, here's each step side by side:

And a big shot of the final "in action" with door and flooring:

Now if I don't get distracted by the in-laws coming to visit, I may even work on some of the other Space Hulk minis and/or my overdue sculpting tutorial. Cheers and hope you've enjoyed!