Dupli-Color makes automotive paints. They're especially famous for touch-up paint, but they make many other paint products too. A popular truck bed coating is one of those other products.
A Dupli-Color liner is designed to look just like a spray on bed liner. You can get the look either with a spray gun or just with a roller. You can get the spray gun or a roller kit from Dupli-Color too. The paint is textured for looks but the texture does more.
It's abrasion resistant too. That's not just the texture material. It's the paint formula too. It's tough paint. You'll want to make sure to get enough paint to put on a thick coat. The thickness of the coating is the key to good bed protection.
Right there lies the trouble with most do it yourself bed liners. The coating just isn't thick enough to do the job. The pro liners like Line-X or Rhino work better at least partly simply because there's more material there. It gets put on faster.
A bed coating is especially right for older trucks. If your old truck bed looks sad and torn, truck bed paint can make it look much better quickly. This coating works well other places too, like inside fender wells. Use it anywhere a thick, durable black coating would work well.
A Dupli-Color bed liner is a fast, fairly easy way that anyone can make a truck bed look better with bed liner paint. And the coating is some protection for the bed too. All this and it's cheap too.
But a better alternative is the DualLiner bed liner.
Or if you want a do it yourself liner look at the Monstaliner or Al's Bed liner products.