I started with painting my Bolt Action Tiger tank with my airbrush, and things seemed to be coming out well so far, so I decided to go all in and do the weathering. Vallejo has a paint set specific to the purpose:
The set contains several paints, including Black Brown (for tracks & paint chips), Buff (sand/dust), Hull Red (rust), a wash for yellow vehicles, a wash for grey vehicles, a mud-colored Pigment, and Pigment Binder.
On the back of the box is a handy instruction chart that takes you step by step through the process.
Paint the tracks in #822 German Cam. Black Brown...
...and once dry, apply a well-thinned layer of #976 Buff and #985 Hull Red.
I apologize for the different tints in the photos, as they were taken in different lighting conditions--the ones with the bluish backgrounds were taken in natural lighting conditions, while the more yellow-tinted pictures with whitish background were taken under indoor lights. In all the pictures the Tiger was placed on a sky-blue piece of posterboard for a background.
At this stage, also apply an overall coat of #513 Wash for German Yellow.
Apply small paint scratches in #822 German Camouflage Black Brown. For this task you can use a small sponge and end the job with a brand new fine 10/0 brush.
Step 2 Apply an overall wash in #513 Wash for German Yellow. For this task use a medium flat brush. Pay a [sic] special attention to the running gear and tracks.
Apply the #104 Pigment well dispersed in #233 Pigment Binder. At this stage, make sure to pay special attention to the tracks and running gear.
I have had very little experience with pigments before, and none at all for the binder. The binder seemed like a great idea--as just putting the pigment on the model makes it look dirty, but it doesn't stay on by itself. I also found out that the pigment dissolves in subsequent layers of paint, so you could spend some time putting on the pigment, only to watch it all vanish when you put the next wash!
With that in mind, I mixed the pigment with the binder, but I had a very high ratio of pigment to binder, as I assumed that all of it would vanish after I applied. I slathered the stuff all over the model.
I was a bit disappointed here, but the model wasn't ruined--in the subsequent step I could try to fix the problem. On the bright side, the mud looked fantastic on the running wheels and tracks.
Step 3 Apply another coat of #513 Wash for German Yellow. This time around the most recessed and rasied parts. At this stage, also apply more fine scratches in #976 Buff and #985 Hull Red, just to add some color variation.
Apply #104 Pigment directly from the jar and once in the desired spots, fix it in place with #233 Pigment Binder.
But wait! I didn't just paint up one Tiger. Tiger 211 has a pair of friends: