Painting Questions

Q. Can I mix Oils and Acrylics?	A.  If by that you mean mix the two paints together, the simple answer is No. You can however do an under-painting with Acrylics and then paint oils over the top, this is useful if you wish to make a quick start but not necessarily of archival quality unless an acrylic emulsion gesso is used.    Why? Acrylics are water based, when you try to paint acrylic over oils, like water on a ducks back it slides off, but this isn't always apparent at first!
Q. Can I mix water based Oils with ordinary Oils?	A. Yes you can. BUT if you mix water based with traditional/ordinary oils, then you need to treat them all as ordinary oils, especially when it comes to cleaning equipment. The modified mediums used with water-based oils were designed for that purpose, and likewise the mediums for ordinary oils.
Q. Do I have to paint Oils on canvas?	A. No you don't, you can use just about any surface for Oils. The only recommendation is that it is suitably sealed and primed, and has a 'key' or 'tooth' for the paint to adhere to, this is very important. You can successfully use solid supports like wood, hardboard, plywood, chipboard, tin, copper, brick, concrete, plasterboard, and pottery. Other supports include oil paper, watercolour paper, illustration board, linen, muslin, silk, polyester and museum board. Plenty to choose from!
Q. What's the difference between, a support, a size and a ground?	A. The support is just that, the material that supports the finished painting, a cave wall or a canvas. The size, which is usually a form of weak glue, penetrates the surface of the support i.e. rabbit skin glue applied to raw canvas. A ground is a physical surface between the support and the paint, it gives a surface texture to paint on, often referred to as 'tooth'. The raw canvas is sized to give it internal protection and strength, a ground is then applied to prime and seal the canvas ready for painting. Why? The ground gives a uniform surface to paint on, without it, the oil paint would soak into the fabric which can cause all types of problems. Over time the acids in the atmosphere can attack all manner of things and even if the fabric of the canvas fell away, the painting could still be intact on it's ground.
Q. What is a wash?	A. A wash is paint thinned with solvent only to a 'watery' consistency, this is usually applied to colour the ground before painting.
Q. What is a glaze?	A. A glaze is a transparent film of colour. The colour is thinned with solvent and painting medium until very liquid, this allows a thin even coat to be applied, to the desired area over the dry painting. Good for depth and colour.
Q. What is scumble or scumbling?	A. Very little paint is used on the brush for this technique. The colour is often opaque, it is used very dry and is in effect 'scrubbed' on, as opposed to painted on to the canvas, good for misty effects and high lights. Very similar to 'dry brush' in watercolour.
Q. What's Impasto?	Impasto is thick and/or rough strokes of paint. A knife is often used for this technique, it is a good way of creating texture.

Q. What is 'Gesso' ?	A. The traditional Gesso is made from hide glue and chalk or gypsum. It is applied to a solid surface and forms a hard, absorbent, ground on which to paint. Gesso is also found in the woodworking industry, where is known as Bole.  There are other Gesso's on the market today, these are often Acrylic and Acrylic emulsion based, quick drying and can be used on a flexible surface as well as a solid surface/ground. Acrylic emulsion gesso is used for priming and is recommended for use with oils.
Q. What is a siccative?	A siccative is another name for a drier, driers are added to some oil paint pigment to make it dry faster but is usually found in oil mediums. Burnt Umber, which is by nature a fast drying paint, (without added driers) when added to other colours causes them to dry faster, it acts as a siccative.
Q. What are Earth Colours?	A. Earth colours were originally made from natural ores of the earth, the main one being iron oxide. Many manufactures now make synthetic iron oxide. The main earth colours are Burnt and Raw Umber, Burnt and Raw Sienna, Yellow Ochre, Terre Verte, (Green Earth) Caput Mortuum, Davys Grey, Venetian and Light Red, there are others but the first five are the main ones people refer to. The earth colours tend to be strong colours that have low chroma and low tinting strength, making them easy to handle. The 'Mars' range of colours tend to be made from synthetic iron oxides.