Rollers are available in two types:
- Natural – made with mohair or lambswool; best with oil-based paints.
- Synthetic – made with nylon, polyester, or a combination; best with water-based paints.
For latex paint, you should use synthetic materials only. For oil-based or alkyd paints, you can use either synthetic or natural material. As with brushes, it’s always a good idea to check the manufacturer's recommendations before purchasing.
Nap (or pile) is the length of the roller's painting surface. Lengths will vary from 1/16 inch to 1-1/2 inch. If you're painting a smooth surface, choose a short napped roller. For a rough surface such as masonry, use a longer nap. Rollers with textured surfaces are also available for special finishes.
Rollers come in widths from 4 to 18 inches. The metal frame for the roller cover comes in two types - birdcage and metal. The birdcage frame works better if you're using fast-drying paints, as it cleans up more easily than the solid-metal type. Most handles are made for attaching an extension.
Trim rollers come in varying shapes and sizes. Cone-shaped types work well in inside corners. Doughnut-style rollers are good for mouldings and other fine work.
When purchasing a roller:
- Look for beveled edges on the roller for a smooth finish.
- Check to make sure the roller has no visible seams.
- Give it a squeeze - it should rebound to its original shape.
- Moisten before use with water or thinner to prevent paint from drying on the roller.
- Load the roller with paint from the slanted edge of the tray to prevent overloading.
- Paint in the shape of the letter W. Start by moving the roller away from you. Without lifting the roller from the wall, fill in the open space.
- Don't try to paint too quickly.
- To clean a roller cover, roll it back and forth on newspaper. Remove paint with the proper thinner. If you're rinsing out solvent-based paint, wear rubber gloves. Let it dry before storing.
- Disposable rollers are available. If you don't plan on repainting soon, you may want to use these to avoid cleanup (especially when using oil-based paint).