Don't skimp on the truck bed paint. Professional spray on linings contain up to five gallons of truck bed paint. Do not skimp on the material you use. A gallon won't cover a full size truck bed well. It requires extra paint and really the more the better. Get at least an extra quart and an extra gallon would be a plus.

The roll on bed liner certainly works much like a far more expensive spray on coating. Do proper preparation and the truck bed paint goes on easily and will stay put for a long time. These coatings work especially well for older trucks that are in bad need of an upgraded look. Are you looking for a bed liner for a pickup? There are several options for protecting your truck. You can get a plastic liner, rubber mats as well as the standard for comparison, the spray on liner. But another way to protect the bed is the do it yourself liner method.  It's a way to get a liner that looks like a professional version but at much less money...

 
 
A roll on or brush on bedliner gets painted on as thick textured paint. The textured part is usually, but not always, many small rubber pieces that impart to the finished coating a sort of cushion appearance and feel. You actually can put the paint on with any regular roller. Truck bed liner paint, you see, is so thick and like a gel that it applies as does a thick paste and then the liquid settles as it dries. As it settles, the roller and brush marks, in fact, vanish and that produces a finish that does look just as if it was sprayed on. That means you skip the spray gun clean-up routine and just throw away the brushes or rollers when you finish. There is more to it than you may think though. My truck now sports a roll on liner and here are a few lessons learned.

Cleaning of the surface that will be painted is a must... The first step is a careful wash with regular water. Just get a can of automotive solvent cleaner. It's acetone or something like it. Put the cleaner on and grease and oil will be wiped away fast. Just because this is so easy, please don't leave out the step.

Remove residue with water and then start sanding. A good sanding also helps to make sure paint sticks. Much like the first point, you cannot start sanding before cleaning. If you do, you drive the wax and grease into the paint and you likely will never get rid of it. That means again that the paint will not stick and the whole project makes a terrible mess.

So it's sanding only after complete cleaning. It is a mistake to sand too much though. The temptation is to really do a good sanding job and get a really fine finish... That's a mistake. A rough sanding works much better. Instead of fine sanding, just use very coarse abrasives and score the surface good and stop at that. Skip the fine sanding.