Touching All The Bases

Choosing paint sheen is as much about personal preference as it is about the amount of wear and tear the painted surface will receive. The sheen or gloss level of a paint — either oil or water based — is the degree to which the coated surface reflects light.

Tint Base

Paint producers provide a number of bases: tintable white, pastel base, light base, medium or mid-base, deep base, accent base, ultra-deep base, and neutral base. Each tint base has a different amount of titanium dioxide, the key ingredient for ensuring the desired color and hiding power (the ability of the dry paint to mask the previous surface color). Different tints work best with different bases.

Titanium dioxide replaced white lead in paint and remains the most expensive ingredient in paint. The annual global production of titanium dioxide is around 4 million tons, and about 58% is used in paint. Titanium dioxide is also used in such products as dry coffee creamer and tooth paste whitener and provides UV protection in sunscreen.

How It Works

Titanium dioxide gives opacity by scattering visible light, while colored pigments give opacity by absorbing light. The more titanium dioxide in paint, the more light is scattered and the more opaque and white the paint appears. Light does not reach below the titanium dioxide layer, so it cannot reveal the color that was painted over. This is why white or pastel colors are more likely to cover in one coat than dark paints which have little or no titanium present.

Universal Tints

Universal tints are coloring materials made up of pigments blended with wetting agents and a liquid, most often a glycol. The pigments dispersed in colorant are either organic or inorganic.

Inorganics give us the earthy muted tones that are popular in the Pacific Northwest. They are very durable pigments and provide good hide.

Organic color pigments produce bright or clean colors but generally are prone to UV light deterioration. Deep reds, yellows, and oranges are notable for their poor coverage and the need for more than one coat to provide hide.

Considerations

The more tint that is added to a base, the longer the paint will take to dry. It will also increase sensitivity to dew, fog, and rain in the curing process and be more likely adversely affect the film integrity. You will need to stir heavily tinted paint longer before use and more often during use.

A tintable white may accept up to four fluid ounces of tint per gallon, while a neutral or clear base may have no titanium dioxide present and can take up to sixteen ounces or more of tint. Using a base that was formulated to be tinted without any added tint will result in poor performance, not white paint.

Because tinting machines can experience technical glitches, always mix the entire batch of paint you need at the start to make sure the color is uniform between cans.

Extender Pigments

Extender pigments are less expensive filler pigments that thicken the paint. They have much less hiding ability than titanium dioxide, but, when used correctly, they can prevent clumping. Extender pigments can also cut gloss and improve flow. When used incorrectly to add bulk and cut cost, they reduce hiding power, durability, and color retention.

Commonly used extender pigments are clay, silica and silicates, diatomaceous silica, calcium carbonate, talc, and zinc oxide. Some low-cost paints, including contractor’s grade paint, use inferior inexpensive fillers; they achieve good hide, but their durability, especially scrubbability, is poor.

Quality

Every paint manufacturer offers paints at different prices. The highest priced paints will have the highest level of quality ingredients. Quality paint generally goes on easier, hides better, and lasts longer.

An all-acrylic latex paint will have excellent adhesion, long-term flexibility, breathability, alkali resistance, scrubbability, and color and sheen retention. The acrylic resin will actually bind the pigments and other solid ingredients to the surface.

Quality paint will have leave more solids on the surface when the liquid — water, in latex paint — evaporates. A solids content over 45% is considered good, and if the paint is top of the line, those solids should be prime ingredients and not inert fillers. The dry paint film should be .002 to .003 inches thick.

Other additives in paint can include stabilizers to prevent paint deterioration on the shelf, dryers to help form the paint film, thickeners to help with paint drips and spatters, preservatives to slow the growth of molds, and mildewcides to inhibit mildew on surfaces.

Some paint labels give lots of information; others don’t. If you have questions about the paint quality, call the toll-free technical support number listed on the label or go online and contact them. Be prepared with the name of the paint and the base code on the label.

Buying Store Mistints

I love good deals and lots of color, so I buy about 20 one-gallon cans of mistinted paint a year, for $5.00 a gallon.
Some of the mistint paint is the right tint put into the wrong base or the wrong tint put into the right base. A mistinted paint may dry lacking both uniformity of color and depth of color.

For the most part, everything I painted with mistint paint turned out well. But I still remember the magenta semi-gloss that needed five coats to hide a white primed surface, the stirred brown that dried with dark blue streaks, and the can of pink paint that oozed red tint from an overfilled can of pastel base.

My rule is to use mistints for painting I can do while standing on the ground. If I have to climb a ladder, I use quality paint I know was tinted correctly.