Pre-Tested® is the name of Grumbacher's professional range of oil colors. It's also the name for a philosophy that permeates the way we manufacture all of our products.

Everything we make is tested again and again at every stage of its existence. Our time-proven formulas are fine-tuned through independent laboratory tests as well as hands-on trial by professional artists. We specify the best ingredients available, putting every new one through a rigorous selection process. We test samples of each and every batch of raw material before we allow our vendors to make shipments. On the factory floor, we sample batches in process. And finally, even after our products are in the field, we continue to track batches and test for quality, performance and shelf life.

Pre-Tested is Grumbacher's flagship. It's the product that, more than any other, represents the way we do business: with care, precision, attention to detail-taking nothing for granted. On a more specific level, it means simply the finest pigments the world can offer, milled in select alkali-refined linseed oil for the professional artist. Pre-Tested stands for optimal color development, high chroma, superior tinting strength, excellent adhesion, outstanding working properties and archival quality.

90 colors, 1.25 fluid ounce (37 ml) tubes. Whites and Ivory Black also available in 5.07 fluid ounce (150 ml) tubes. Made in the U.S.A.

USING OIL COLORS

• Choose a good quality, stable support-stretched canvas or wood panels are most often recommended.
• Raw canvas should be sized before priming by brushing with hide glue or acrylic matte medium. Prime the sized canvas with acrylic gesso or white lead primer.
• Never mix oil colors with acrylics or paint acrylics on top of oils. You may apply oil paint on top of acrylic gesso so that is thoroughly dry.
• Use mediums and thinners to alter characteristics such as flow, transparency, gloss and drying time.
• Oil paintings should be varnished only after the painting has cured (6 months for a thinly painted painting and 12 months for a thickly painted painting).
• Protect the surface of a finished painting with a removable varnish. Dirt, dust and smoke discoloration's adhere to the varnish over time and can be removed along with the varnish to restore the painting.
• Oil paintings will yellow if left to dry in the dark. Let them dry in normal room conditions, avoiding direct sunlight, high humidity or other severe conditions

PAINTING "FAT OVER LEAN"

• Multi-layer oil painting techniques in which paint is fluidly applied require that "each layer of an oil painting must contain more oil than the layer underneath". This allows for proper drying and adhesion between paint layers and deters cracking of the painting when it ages.
• To ensure a "fat over lean" ration, pour a quantity of oil or painting medium into a container and dilute with a larger amount of solvent. Mark the level of the mixture on the container. Fill the palette cup from this container. When a layer of painting is completed, allow it to dry. Then refill the container up to the mark with straight oil or painting medium. Repeat each time a layer is completed, adding oil or medium up to the mark on the container for each session. This will automatically increase the ratio of oil in each layer.
• Wet-in-wet or alla prima painting techniques, in which paintings are completed in one or two sessions without allowing layers to dry, do not require adherence to the "fat over lean" rule. Such paintings effectively form only one paint layer, so the rule does not apply.

All Pre-Tested Oil Colors are available in 1.25 fl. oz. (37ml) tubes. Several colors are also available in 5.07 f. oz. (150 ml) tubes.

WHITE OIL COLOR

Large Size Colors 5.07 fl. oz. (150 ml)
P069-11 Flake White
P212-11 Titanium white (original Formula)
P115-11 Ivory Black
P250-11 Titanium White (Soft Formula)
P248-11 Zinc White

Flake White
A permanent, very heavily bodied, opaque, warm white. Having a reputation as the most permanent of all whites, Flake White is ideal for heavy impasto applications or where several layers of color must be built up.

Zinc White
A permanent, heavy-bodied, semi-opaque, cool white. Designed especially for brilliant clear tints with all oil colors and excellent for glazing

Titanium White (Original Formula)
A permanent, heavy-bodied, versatile, opaque, pure white-neutral in hue. Ideal for all applications where great opacity is required.This is the strongest tinting white.

Titanium White (Soft Formula)
A permanent soft-bodied, opaque, non-yellowing Titanium White ground in poppyseed and sunflower oils. Also recommended for fluid wet-in-wet techniques.

OTHER WHITES

Suberba™ (Titanium) White
A medium bodied, premium quality, non-yellowing, highly pigmented opaque Titanium White. Ground in traditional walnut and poppyseed oils.

MG® Underpainting White
A permanent heavy bodied, quick drying titanium white for underpainting. Extremely useful for creating surface textures. Should be used on rigid surfaces only.