One of the most versatile painting systems invented is the paint roller. The paint roller can apply the same amount of primer or paint in half the time it would take with a brush. It is perfect for large flat areas, such as walls or ceilings. A good roller setup consists of the roller cover, frame and extension pole. These pieces are combined with a 5 gallon pail or specialized paint pail and a roller grid.  This paint application system will last a long time, requiring only the occasional new roller cover and grid.
 
Width
The frames and covers are available in widths from 3 inches too 18 inches. The most common sizes are 7 and 9 inch, perfect for most painting projects. The wider 12 and 18 inch systems are for covering large area fast. While the 3-4 inch rollers are normally used on exterior trim, but could find a use with closet shelving.
 
Paint Roller Covers
There is a wide variety of materials used in the construction of a paint roller cover. These materials range from natural fibers to synthetics and combinations of the two. The term pile refers to the thickness of the fibers used.
• Common natural fibers used are mohair, goat's hair, and lamb's wool. A mohair roller has a very tight pile, making it a very good choice for ultra smooth surfaces like metal doors. Mohair roller covers are a great choice for oil base paints and varnish.  Lamb's wool is a standard in the industry. Available pile thicknesses range from 1 1/4 – 3/8 inches thick. The thickest piles, 1 and 1 1/4, are for very rough surfaces and 1/2 – 3/4 are for lightly to rough textured surfaces. 3/8 thickness is a good choice for a smooth or very lightly textured surface. Lamb's wool roller covers can be use for both oil base and acrylic primers or paints.
• Synthetic fibered roller covers are used for latex/acrylic paints or, if an inexpensive cover is chosen and thrown away, used with oil based primers. Synthetic roller naps thicknesses range from 1 1/4 – 3/8.  Sponge is another type that is suitable for ultra smooth surfaces.
 
Paint Roller Frames
A good paint roller frame is a critical part of your paint roller system. Fortunately, these are inexpensive and last a very long time. The choices include the size and cage design, plus the method that the roller frame attaches to the roller extension pole.

The size, measured in inches, is the same as the covers. An example is, use a 9 inch frame for a 9 inch roller cover. Simply choose a paint roller frame that fits the cover size you want to use.

The next consideration is the cage that holds the cover. Cheaply made roller frames allow a lot of slippage of the roller cover. This makes rolling the paint difficult and frustrating. The better frames have 5 wire cages or a positive locking spring mechanism for better grip.
 
Paint Roller Extension Pole
A good cover and frame doesn't do you much good without a paint roller extension pole. Why go up and down a ladder or reach and work harder when you don’t have to. An easier time rolling your paint is what an extension pole offers.

This simple and effective accessory is available in many lengths for reaching almost any surface. Choose from 1-2ft, 2-4ft, 4-8ft, 6-12ft and 8-16ft.  The most convenient sizes are 1-2 and 2-4ft.

Just like every other type of tool, there are good ones and not so good ones. The cost difference between good and not is just a few bucks.
 
The Paint Pail and Roller Grid
You have a choice to use a paint pan or a bucket to hold the paint. The use of a 5 gallon bucket instead of a paint pan is highly recommended. The bucket will hold more paint, be easier to move and remain more stable.

A paint pan has its uses, such as rolling small areas for touch up. But, for rolling an entire room with a 9 inch roller, a standard 5 gallon paint bucket with 2 gallons of paint in it will be more efficient and safer.

A 5 gallon bucket will work for 7-9 inch standard rollers; specialized square buckets are available for the commercial 12-18 inch rollers. For the mini rollers or smaller standard paint rollers use a 2 gallon bucket.

The commercial buckets for 12-18 inch rollers have a grid built in for removing the excess paint from the roller nap. For the other buckets use an appropriately sized paint roller grid. These are available to fit 1 gallon cans or 2 and 5 gallon buckets.
 
Mini Hot Dog Paint Rollers
Theses are the neatest paint rollers around. Hot Dog Mini Paint rollers are exactly what the name implies, skinny paint rollers with lengths from 4-6 inches and frames choices from 12-16 inch in length that can get into difficult areas to paint. Perfect for behind a toilet or heat register.

That isn't the only uses. Great for rolling doors or cupboards and shelves on interior surfaces plus they can be used for exterior trim. Hot Dog Mini Paint Rollers will speed up the painting of many difficult to reach surfaces.

Mini roller covers are available for a wide variety of different types of paints and finishes. These range from sponge and tight weave covers for oil base paints and varnish to thicker covers for regular house paint.
 
Specialty Paint Rollers and Covers
Paint rollers and covers are designed for a variety of different circumstances, ranging from painting pipes and balusters to creating different wall textures.  Use these specialty paint rollers for difficult jobs or when something unique must be done.