What Does a Thicker Roller Do to Paint?

Roller ABCs

• Thick-nap rollers have fabric from 0.75 to 1.5 inches deep. Natural lambskin and mohair have excellent “pick up” and release qualities, but also are very expensive. Many professionals choose a wool-polyester blend. It is a bit less expensive than lamb’s wool but worth the price because of its durability. The most popular rollers are polyester and other blended synthetics as they are inexpensive enough to dispose of after one or two uses. A plastic core covered by the densest weave in any type of fabric lasts longest, but also might be very expensive.

Stippling

• The thick-nap roller excels on uneven surfaces, such as concrete or stucco, because it pushes paint down into openings. Use it on a smooth surface and several problems might occur, stippling being one of the most common. A plain wall offers no challenges, and the thick nap bunches and spreads as it rolls over the surface, leaving waves of tiny lumps called stipples. The effect is very noticeable with thicker alkyd, glossy or semi-glossy paints.

Spattering

• Load a thick-nap roller with paint, especially thin latex paint, and it will spatter as you roll a smooth surface. Thick nap rollers carry enough paint to cover stucco and masonry. On smooth walls, there is too much paint and too little surface to put it on or in. Spattering may occur in the area where the painter is working, or in another part of the wall, ceiling or floor. Heavy spatters also might drip or sag as a result of uneven coating.

Bubbles

• Also known as foaming and cratering due to the rising and bursting impressions left in drying paint, bubbles result when a thick-nap roller is worked back and forth too quickly in an effort to cover a smooth wall evenly. The motion works air into the paint just as shaking a can might. Gloss and semi-gloss paints bubble easily because skins form on their surfaces that hold back any air floating to the top.