A rollback coat is influenced heavily by the density of the undercoat. The guard hairs provide protection and stability to the underfur, but the undercoat makes for both density and that rollback action. In fur with a less dense undercoat, you end up with a flyback coat. Satin fur is not technically classed as either flyback or rollback, but if you're getting a snappy return, you know the coat is lacking density especially in the underfur. In Holland Lops (a rollback breed), we find the best coats are also the ones with heavy underfur.
As
@judymac suggests, the best approach is to breed rabbits with the most dense coats, and then select the kits with denser coats as your next generation. No matter what you cross into your line, that basic method is what you need to get you where you want to go.
Honestly, since you don't seem to be breeding to a particular breed standard, just going out and finding rabbits with great density would probably be the way to go. But for thinking about possible crosses, common breeds calling for rollback fur include American and Standard Chinchilla; French, Mini and Holland Lop; and Flemish Giant. Less commonly found rollback breeds are Blanc de Hotot; Beveren; American Sable; and Lilac.
If you are breeding meat rabbits, the most appropriate crosses would be the Sable, AmChin or Blanc de Hotot, as they have commercial type and medium bone as well as rollback fur. Lilacs and Standard Chins are slightly smaller (5.5-7.5lbs and 5 -7lbs respectively) but still have good meat rabbit type. Mini Lops, slightly smaller yet, call for heavy bone, but you can find them with lighter bone (those will generally be culls for that reason). French Lops are huge with massive bone (not at all desirable in a meat rabbit); Beverens have a mandolin or semi-arch body type; and Flemish have both massive bone and a mandolin shape. Mandolin type does
not mean they aren't good meat rabbits - Beverens certainly can be - but be aware that crossing to them will tend to result in long shoulders on some of your meat rabbits.
One possibly surprising cross that breeders have often used to increase density in their rabbits is Rex, which has a coat type characterized by an unusually high density of hairs per follicle (though not all rex have good density - you have to be choosy). The issue is that since rex is a recessive coat type, you'll find yourself getting rexed kits at various points down the line. Strangely, while adding rex can be a good way to increase density in the normal coat, I've found that rexes resulting from such a cross tend to lose that incredible density.
Same with angora - I know people who have used an angora with great density to increase density in their rabbits of another breed. When my daughter was playing around with making Satin Angoras out of Satins x French Angoras, we did see increased density in many of the normal-furred offspring. But like the rex, the angora gene will lurk and pop out fuzzy babies from time to time.
The point is that whatever breed or crossbreed you use, just make sure it has outstanding density itself. One way to assess this is to blow into the coat, or roll it back with your hand. As the old adage goes, "If you see skin, it's too thin."
I've found that Satin juniors that look just a bit wooly or fuzzy - because their undercoats are well-developed before they get their adult guard hairs in - are the individuals that tend to develop into the rabbits with the densist coats. The really sleek youngsters are flashy but tend to have less density as adults.
Another interesting thing I've found, though I can't say whether it holds true with other breeds or not, is that if I breed blacks with blacks for more than a generation or two, I start losing density. My blues almost always have great density, and even if I didn't love the blues, I'd keep them around to help my black coats stay dense. I'm also recently finding the same advantage to using REWs with my blacks (but so far, have not found it with himis).
