Is this the picture you speak of? If it is It is very likely trunk spatter paint or the hammertone type paint. I'd have to say its the trunk spatter. You can buy it in a few different color choices in rattle cans. Its available almost anywhere anymore even wally world, I beleive Dupli Color brand has the line of the trunk spatter. you could also go to eastwoods site they sell hammertone as well as trunk spatter.
Actually no, it is a very tough paint. Think of it as two layers of paint. Its not like the stuff you buy at wal mart or k-mart for home use that has a rough texture. Its basically exactly like it said a coat of base with "spatters" of other colors. you could do the same thing with any type of paint. If your old enought to remember spiderwebbing that was the same basic idea, but instead of "splattering" the paint a thick consistency of paint was spit out through a spray gun. Its as durable as any other painted surface.
Those spatter trunk colors alll come in the same can. They have a base color and a couple of incompatible accent colors. When sprayed, the base color wets the surface and the accent colors, being inompatible with the base color and each other, just sit on the surface. Applied alone the paint is very delicate and will wash off with water. However, it is a two part system so a clear coat is sprayed over the color. Once clear coated, it is as tough as any coating out there. I wouldn't have any problem painting an engine bay with it if that is the look I wanted.