Viscosity is described as the thickness of paint. The higher the viscosity, the thicker the paint. It is a property in both alkyd and latex paints that resists flow and movement by force.

The solvent used in the paint adjusts the paint's viscosity (mineral spirits in alkyds and water in latex paint).

Viscosity in paints is measured with a device called the Stormer Viscometer and is read in units called Krebs.

Higher Viscosity: Flat paints (90-100 KU or krebs units); have poor flow properties, but thick to thoroughly cover the surface with heavy application

Medium Viscosity: Gloss paints (80-90 krebs units); still have good flow properties while allowing a heavier film application

Lower Viscosity: High gloss alkyds and latexes (70-80 krebs units); allows smooth and even flow

Hiding Power is the ability of a paint to cover up the surface and/or previous paint film. 'Hiding' is the degree to which a coat of paint covers the surface. Paint said to be hiding well will mask the color underneath completely or almost completely. Paint with less hiding power will not cover the color underneath as well.

Hiding is controlled primarily by the amount of titanium dioxide in the product as well as extender pigments.

Titanium is a white pigment and is the most expensive ingredient in paint. Therefore, the more hiding power, the more titanium involved, and the higher the cost of the paint.

Scrub Resistance is the ability of a paint film to resist abrasive cleaning that might wash the paint film off the surface.

Scrub resistance may be directly related to the ratio of resin to pigment in paint; the more resin in the product, the better the scrub resistance.

Resin = Scrub Resistance

Extender pigments also play a key role in scrub resistance.

Examples:

Economical flat paints are loaded with pigments. When a surface covered with this type of flat paint is wetted, it becomes very porous and absorbent. Marks or stains absorb into the pigment on the surface of the paint's film. When the surface is washed, the paint may be removed with the marks. There are, however, premium grade flat or velvet sheen paints that have excellent scrub resistance and stain removal characteristics.

High gloss products have a resin coating on top of the pigment that protects the pigment from stains and abrasions.

Porosity is directly related to the pigment/resin ratio as mentioned above in Scrub Resistance.

Therefore, high gloss paints tend to be more stain resistant since they are less porous.

Flat paints tend to be porous and less stain resistant. Some flat or velvet sheen paint products have been formulated with special stain resistant properties, but these properties also make the paint more expensive.

Sag Resistance is a characteristic that slows or stops the flow of paint downward to prevent excessive running of the paint as it is applied.

A product's Sag Resistance level is determined by the quality of finish appearance expected.

Sag Resistance is directly related to viscosity.

High gloss products have a much lower sag resistance than flat products because they must be allowed to flow enough to produce a seamless, unmarked appearance when applied. When dry, gloss products show all the imperfections on the substrate because they reflect light, whereas flat products do not.

Fineness of a paint product is a test done in the lab to measure how small the pigment particles have been ground up/dispersed when the paint was being produced.

Fineness test is done on a Hegman Fineness Gauge, related in units of Hegman.

Flat products = fineness range of 4-5 Hegman
High gloss products = fineness range of 7-9 Hegman

High gloss ranges are higher than flat products because gloss products show more surface imperfections when dry.

The ingredients used in paint determine the odor control. This odor is controlled to a large degree by the quality/type of resin and solvent used in the production process.

Most customer odor complaints occur with alkyd products used in interior application. Proper ventilation is required for all paint applications, whether latex or alkyd.

Color is a quality requirement of paints used to decorate and enhance an individual's environment and is interpreted by each individual.

Variations in color occur when tinting the same color in alkyd products vs. latex products vs. gloss products.

Color chips are produced using flat latex paint; latexes are produced with a resin that is white in color. Tinted alkyds tend to have a somewhat yellow tone when compared to the color chip. Alkyds are produced with a resin that is honey toned in color. Tinted glosses can be a good match to the color chip, but the gloss can make the paint look like a different color. Also, the type and intensity of light can alter a person's view of what a color will look like on a wall.

Make the customer aware how light and alkyd or gloss paint will look different than the latex color chip. To show the paint transformation to a gloss finish, you can wet the color chip or put a piece of clear scotch tape over the color chip.

Gloss = what you see from an angle of about 30 degrees from the surface.
Sheen = what you see as you look along a wall at about a five degree angle from the surface.

Both gloss and sheen are measured with a gloss meter, a delicate instrument that measures gloss/sheen at angles of 20, 60 and 85 degrees, to cover the complete range of formulated gloss levels in all paints. The purpose of a gloss meter is to control and continually reproduce consistent paint at the same gloss/sheen level batch after batch.