Roller covers, like brushes, are available in various qualities and can be made with natural fibers or synthetic fibers. Just like brushes, the higher the quality of the roller cover, the easier the painting and the better the results. Roller covers are available in many sizes. There are trim rollers, corner rollers and roller covers for other special applications. However, the two most popular lengths of roller covers are 7" and 9"; with 9" being the most popular of the two. Roller covers earn their "cover" name from being used on roller frames (which come in many different sizes, shapes and types of handles). The most common frame is a "five wire cage" frame that is made with five parallel wires that help to maintain the round shape of the cover. Most higher quality retail frames and generally all professional frames have a threaded handle to permit the use of extension poles for painting floors, ceilings and tall walls.
Selecting the correct roller cover can be a quick exercise... if you know the right questions to ask. It's as easy as 1 - 2 - 3.
By knowing the surface (i.e. wall, ceiling, fence, etc.) will determine the correct nap and degree of finish required (is some texture permissible or does it require enamel smoothness?)
The type of paint helps in determining the degree of "texture" the user feels is permissible. Roller covers made with natural fibers like wool or mohair are usually recommended for oil-based paints, varnishes and stains. Synthetic fiber covers (usually a blend of fabrics like polyester, nylon, rayon, and acrylic) are used with latex, oil and alkyd paints
The last question establishes the strength and durability requirements (will the cover be in constant / repeated use or simply "tossed-away" when the job is done?
Putting it all together - A roller cover is comprised of a core and fabric(s) which are adhered with epoxy adhesives to the core. Higher quality retail and professional covers are buffed and beveled. Roller cover cores are plies of cardboard, usually 3 - 4 ply. Better cores are impregnated with a phenolic resin to provide strength and durability. Less expensive cores for "toss-away" covers are untreated and have only the cardboard material as the core itself. Some companies do produce a plastic core which, under heat and constant use can "out of round".
Woven Fabricsare attached to the backing of the roller fabric at two points, thus ensuring the most lint-free type of cover available - for the application of coatings on smooth surfaces.
Knitted Fabrics are attached to the backing at one point. This process is used on covers where lint is not an important factor in the end result.
For smoother lint-free results with all paints, use awoven roller fabric—especially with higher-sheen coatings. For greater pickup and release (faster application), try aknitted fabric when using flats or stains.
"Nap" or pile is a term that is frequently used to describe the fabric pile height. It also affects the depth of paint reach in the application process. For example, if the surface is extremely rough (like heavy stucco), then a large nap like 1" or 1-1/4" would be appropriate. If the surface is very smooth or a fine finish is required, then a 1/4" nap would be the right choice
Choosing the right Nap:
Generally, the smoother the surface the shorter the nap.
3/16” or 1/4” nap:Untextured plaster, smooth wood, drywall, wallboard, metal. Fine Finishing.
3/8” or 1/2" nap: Most walls and ceilings. Lightly textured drywall or wood, acoustical tile, paneling, smooth concrete.
3/4" or 1” nap: Textured plaster or stucco. Siding, decks, concrete block. 1 ¼” or 1 ½” nap: Heavily textured plaster or stucco. Rough wood, brick or corrugated metal.
Fabric pile height or nap, as previously discussed, is the length of fabric from the core that determines the depth of surface or profile which can be painted. Fabric density is how solid the fiber is per square inch and how many fibers there are per square inch. The more fibers, the better the cover. Fabric Denier is the diameter of the fiber. A roller cover has varying deniers. Using fabrics with higher density and various deniers also increases resistance to matting thus, improving paint pick up and release. Higher quality covers are finished off with a buffing to remove all loose fibers and then beveled at the ends to prevent splattering. This finishing provides easier cutting in of the paint.
Let’s look at some characteristics for some popular types of roller fabrics:
Synthetic: Broadest category of paint roller cover fabrics. Made with a single fiber type of a blend of fabrics. Common materials are polyester, nylon, rayon, and acrylic. Can be used with waterborne or oil-based products. Quality varies from professional to economy.
Shearing: Wool that is still attached to its tanned skinned also called lambswool, lambskin, or sheepskin. Naturally shed-resistant, exceptional capacity and release.
Velour: Woven together with synthetic fibers, velour covers create a smooth, glass-like finish, and resist matting. They provide superior results and are ideal on smooth surfaces.
Microfiber: Unique fabric with a velvety texture. High density with tiny fiber tips to deliver excellent finish quality. Good paint release, even coverage, minimal stipple.
Polyamide: Yarn-like fabric that offers high capacity and durability. Bulk and thickness of the twisted tufts make it great for rough surfaces.
Foam: Guarantees a “lint-free” finish because there are no fibers in this paint roller material. Smooth results, but very low paint pick up and release. Ideal for smooth surfaces.
Tips for Roller Cover Use
Before painting with a roller, "ruffle" the pile to make sure any loose lint, dust or pile is removed. If you suspect there may be some loose pile and the paint job may be affected, pre-roll some paint on a paper or another smooth test surface to make sure all loose pile is removed, and the finish is acceptable. Don't overload the cover with paint. Roll out lightly on the paint tray or grid to help distribute the paint evenly and prevent "dumping" on the surface. Painting too fast with a roller causes splattering and misting. A steady pace will get the job done quickly and neatly. Deposit the paint in a "W" pattern on the surface to be painted. Roll out evenly in one direction then cross roll to assure the paint is uniform. Finish strokes should always be in the same direction. Avoid pressing too hard on the roller as this spreads the paint too thin. Do ladder work first. Clean up should be done immediately after painting, using the recommended solvent (warm soapy water for latex paints.). Store the roller on end to prevent matting of the fiber as the roller cover dries.
Remember, the better the quality of the applicator tool, the better the results!
Let us look at the features and benefits of the Roller Covers we carry in our store!
Wooster Pro/doo-Z FTP Roller Cover (Woven)
Wooster Super/Fab Roller Cover (Knitted)
Benjamin Moore Aura Roller Cover (Woven)