Everything you need to know about oil primers
Alkyd medium can be used as a painting medium and as a glazing medium. Used as a painting medium, the "fat over lean" rule should be followed. The medium is quite fat and can be made leaner with a quantity of white spirit or turpentine. In the final coat and for glazing techniques, Alkyd medium can be used pure. It is slightly yellowing, shortens the drying time and increases the durability of the paint film. The gloss of the paint becomes slightly higher, the brush stroke fades.
A quick-drying medium consists of the same ingredients as a regular medium, but with the addition of siccatives. The drying of linseed oil takes place chemically. The oil absorbs oxygen from the air, linking the molecules together in rigid chains. This process takes a long time and explains why oil paint dries slowly. Now, if we want the paint to dry faster, we need to add something to the paint that allows the oil to absorb oxygen faster. This is done using solutions of certain metal compounds called siccatives, which can be added either directly or through a medium. Siccatives can also be bought pure and can cause problems if overdosed. The amount in Talens quick-drying painting medium 084 is safe for the durability of the workpiece.
The purpose of a medium is to influence one or more properties of the paint and make it suitable for a particular application. These include consistency, gloss, flow, drying time, transparency and durability of the paint film.
Venetian turpentine gets its name from history. The turpentine balsam extracted from an Austrian larch used to be traded via Venice. This traditional glazing medium is valued for processing properties that positively influence gradual colour transitions, but does not promote paint film durability. The medium increases the flow and gloss of the paint, slightly shortens the drying time, is slightly yellowing and is dilutable with turpentine or white spirit. Use only in final coats.
Painting paste, popularly called painting butter, is an unpigmented (colourless) oil paint. The medium can be mixed with oil paint in any proportion without changing the colour and consistency of the paint. Thus, more paint can be made from very expensive colours. Painting paste can also be used to prevent scorching of certain colours in thick layers. A mixing ratio of 1:1 is sufficient for this. Painting paste does not yellow and increases the durability of the paint film. The paint becomes slightly more matt and the drying time slightly shorter.
Talens glazing medium is the modern replacement for traditional glazing mediums such as stand oil and Venetian turpentine. Differences are mainly expressed in a more durable and non-yellowing paint film. The medium increases the flow and gloss of the paint, has no effect on the drying time and is dilutable with turpentine or white spirit. Only use in the final layers.
Whether a painting is painted wet-on-wet or in layers, a glaze can be applied as a final layer. A glaze is a transparent layer of paint whose effect can be compared to that of a coloured sheet of glass placed on a particular picture: the picture does not change, the colours do.
How do you get the next layer fatter? Which products should you take then. Add more alkyd or in the first layer 007 Alkyd + 090 White Spirit Artist' Grade. That way you make the oiliest medium slightly less greasy and you can build up from there by adding more Alkyd medium with each coat.