DERIVAN MEDIUMS      

These mediums add even more versatility to the Student range, unlocking the door to many different and varied techniques.

Acrylic paints are very versatile because they can be manipulated to achieve a myriad of effects; for example, the addition of water to create a watercolor or wash effect. There are many different "painting mediums" to help change and manipulate acrylic colors so that an artist can achieve almost any effect.

SPREADER MEDIUM - 500ml & 2L

Derivan Student grade acrylic paint offers a thick consistency suitable for impasto, oil painting and brush stroke techniques but its high tintorial strength allows for ready dilution with water or mediums giving the painter free expression by selective use of these mediums.

One such medium is "Spreader Medium" and the purpose of this medium is to spread large volumes of transparent color over selected areas while maintaining a controlled paint viscosity. Acrylic color can be added in small or large increments to the Spreader Medium. Spreader Medium is a transparent flowing paste. It dries fairly "flat" and when dry can hardly be discerned on a painted or unpainted area, i.e. it leaves almost no stain.

Its main application is for glazing where it imparts fine flow and controlled spreadability and lubrication to the paint. Used on its own, the medium does not dry waterproof and can therefore be used as an intermediary between two partially dried paint films if some water sensitivity for wash areas is desired.

Applied over a dried paint film, it gives a wet effect but will recede to an almost invisible film when dry. As Spreader Medium dries relatively slow when applied over a well-primed or heavily painted area, it increases workability within the paint.

Soft color hues and delicate tone on tone can be obtained by using Spreader Medium.

Spreader Medium can be used to pre-dilute Derivan acrylic colors to infinity thereby increasing transparency (this may also increase water sensitivity).

Polymer Gloss Varnish is the natural intermixer with the spreader to increase water resistance Pre-addition of 1 part Polymer Gloss Varnish to 4 parts Spreader Medium is sufficient to impart water resistance to the medium.

IMPASTO MEDIUM - 500ml & 2L

This medium is a heavy-bodied paint, free of color pigmentation (it isn't a gel).

It is most valuable for oil painting brush stroke and impasto techniques, particularly when heavy built-up areas of color are required.

Impasto Medium dries to a low subdued sheen which is similar to the sheen on a dried paint film of acrylic color.

It is equally water-resistant.

Impasto Medium allows for free intermixing with the Derivan colors in any proportion. There is little visual color loss when equal volumes of a Derivan color and Impasto Medium are intermixed. Although Impasto Medium is not fully transparent when dry, it does not appear to alter the richness of Derivan colors in any way. Impasto Medium is also suitable for use as a light modelling compound.

It can be applied by knife or brush in heavy blobs onto the original primed canvas and when dry, fully over-painted with Derivan colors.

Do not use Impasto as a transparent glue or size where its slightly milky opacity could cause some discoloration. However, it makes a high quality acid-free glue or size where transparency is not a concern.

PRINTING GEL - 500ml & 2L

Printing Gel is used in silk screen printing with Derivan acrylics.

Student grade actrylic can be mixed with Derivan Printing Gel to keep the colors from drying and clogging the screen mesh. Using this medium, many prints can be made at one time without having to clean the mesh between every print. Screen printing can be done on paper, board or fabric. For fabric printing such as on to clothes, use Derivan Fabric Fixative in conjunction with the acrylic colors.

Printing Gel is also used to reduce color strength when transparent colors are required for printing. Mix the Printing Gel into the color until desired transparency is reached.

Printing Gel is also an excellent inexpensive craft glue.

GESSO - 500ml, 2L & 4L

Derivan Gesso is a great primer for canvas, board or even paper.

The strong white ground gives an excellent tooth for easy paint manipulation.

Being a water-based product, Derivan Gesso can be thinned down with water if desired. If working on canvas, Derivan Gesso will tighten the canvas when dry giving a taut ground on which to paint.

Derivan Gesso can be used to paint over old acrylic works to give the artist a like new surface to paint on. If more than one coat is desired, then it is advisable to sand lightly between coats to obtain a smooth finish.

RETARDER - 500ml

Retarder as the name suggests, retards or slows the drying time of the paint.

There are two ways to use this medium. The first is to use up to 3% Retarder to color; this will result in a slightly more fluid color that will stay wet for much longer. The second method is to put the Retarder in a hand pumped spray bottle (atomiser) and spray it onto the painting you want to keep wet. (The spray bottle should create a mist not a hard squirt).

Additions of drying retarder to mixing water may be used in water coloring, water wash effects, stain painting and hard edge techniques where it assists in pigment wetting, rapid color diffusion and penetration.

GLOSS VARNISH (turps) - 500ml

This medium produces a hard non-yellowing, clear protective coating with a high gloss finish; a final clear varnish, quick drying, designed to give your painting that final touch.

For a glass-like gloss, allow the first coat of varnish to completely dry before applying a second coat.

Strippable: The varnish re-dissolves in mineral turpentine which has very little effect on acrylic paints: thus a painting may be completely cleaned and re-surfaced without affecting the paint. Ideal for use in restoration (may be used on oil painting). Also called Retouch Varnish.

Warning: Acrylic brands may vary. Do not varnish any painting without doing a trial test.

Special Note: To achieve a satin finish, pre-mix the Gloss Varnish (turps) with the Matt Varnish (turps) until you achieve the desired amount of sheen. These two turps-based products will intermix with each other but will not intermix with the water-based mediums.

Health and Safety Note: This varnish contains mineral turps and should be treated as a hazardous material. It should be applied in a well ventilated area and kept out of reach of young children. Clean brushes in turps.

MATT VARNISH (turps) - 500ml

Produces a hard, non-yellowing, protective coating with a flat non-reflective finish.

It is totally transparent.

Strippable: The varnish re-dissolves in mineral turpentine, which has very little effect on acrylic paints; thus a painting may be completely cleaned and re-surfaced without affecting the paint. Ideal for use in restoration (may be used on oil paintings). Also called Retouch Varnish.

Warning: Acrylic brands may vary. Do not varnish any painting without doing a trial test.

Health and Safety Note: This varnish contains mineral turps and should be treated as a hazardous material. It should be applied in a well ventilated area and kept out of reach of young children. Clean brushes in turps.

POLYMER VARNISH - 500ml & 2L

This Gloss Medium can be used as a gloss finishing varnish and as a glossy additive to the paint.

Mixed with Derivan colors, it increases gloss and flow characteristics. Used as a finishing varnish, it produces a strong, protective, tack-free, clear film.

Pictures treated with Polymer Gloss will appear to look like work done with oil paints or shiny enamel. Polymer Gloss Varnish is freely intermixable with Derivan Acrylics.

It is water-based and may appear slightly milky whilst wet. This is an optical effect produced by light refraction of acrylic particles suspended within the water-based film. The effect disappears when the film is dry.

As acrylics dry very rapidly, care should be taken to apply varnish pre-diluted with water (as per directions on labels). Polymer Gloss Varnish applied in very thick layers on a hot day could trap moisture, resulting in a cloudy film which would be very difficult to correct, e.g. all Derivan painting mediums are freely intermixable - Polymer Gloss Varnish will intermix with Spreader Medium to give a glossy glaze effect (however, do not mix turps varnishes with other mediums). Nevertheless, painters are advised to use some discretion in pre-determining their selection of mediums to avoid unwanted effects.

VISCOSITY THICKENER - 115ml

This is an additive that is meant to be stirred into the color to give a thick buttery consistency.

Originally it was formulated to give the perfect paint thickness for screen-printing. However, it is now widely used to thicken colors to achieve an impasto effect in painting.

Add 2 teaspoons of thickener per 250ml of paint. Use sparingly as this a very effective medium (not compatible with fluorescent colors).

Paint that has been thickened with Viscosity Thickener should be used within 48 hours or so.

FABRIC FIXATIVE - 500ml

If washproof fabric paint is required, Derivan Fabric Fixative mixed with Derivan colors will become permanent on clothes after heat fixing.

Mix equal parts of Fabric Fixative and Derivan colors, then paint and let dry before you heat set with an iron to make the garment wash-fast.

Some synthetic fabrics are non-absorbent and thus not suitable for paint application. Test your fabric beforehand. Also avoid applying the paint too thickly as this may cause the paint to crack.

Heat Fixing Prints

It is necessary to heat fix the image. To render it washproof. Heat fixing can take many forms. The main points to be observed are:

•  The image has been air dried before it is heat fixed.

•  When heat fixing, the heat is applied evenly over the image.

•  The heat is applied continuously for the required time over the image.

•  Be sure not to scorch or burn the image or garment.

•  Any type of heat can be used. Heat tunnels, ovens, even the humble household iron, can all be used. If using contact heat (for instance an iron), use a tea towel or another piece of cotton cloth over the image to iron on. Do not iron directly over the print.

Heat Fix Times and Temperatures

Heat fixing times and temperatures vary. However, a guide is as follows:

•  Cotton, calico, linen, rayon - 4 to 5 mins at 140c -180c.

•  Synthetic, nylon, polyester, tetron, acrylic 5 to 8mins at 115c -130c. Important projects warrant a test. Tests should always be done on the fabric to determine maximum temperatures (to avoid the fabric or the image being scorched or burnt) and times required to make the image fast. Test by heat fixing a test strip and washing in a heavy-duty cycle