Once the ballast is dry, it is time to make those perfect railroad ties look like they've been there a while. The first thing I do is to use the famous India ink and rubbing alcohol mixture to put some dark shadows in the ballast. I simply use a soft brush and cover the entire area. I let it dry for an hour or so.
Next, I use a fairly stiff brush and dry-brush acrylic white paint over the ties. I also dry-brush this same white over the tops of the ballast. This is especially effective on the darker bits of ballast, because it makes them look like rock. If you get too much white paint on the ties, simply use your finger right away and wipe it off. That gives a nice effect also. Don't wait too long because this paint dries very fast.
The next photo shows the difference between "aged" and pre-aged ties. Also note the subtle difference between the darker pieces of ballast on the left and the ones on the right. Dry-brushing really makes a difference.
