Paint Workshop : Paint, Mediums and GlazesPosted: February 19, 2014
Today, I attended an incredibly interesting workshop, where the tutor talked about paint, mediums that we can mixed with both oil paint and acrylic paint, varnishing, adding colour, layering colour and glazing with many layers of paint. I learnt so much this morning and I will outline all of the things that learnt during this workshop below.
Oil Paint and Acrylic Paint is made from the same pigment. Burnt Sienna is an exception to this rule, as art students we probable rarely use real burnt sienna pigment, it is now mostly synthetic. Certain pigments within paint have certain qualities, for example Naples Yellow has a thick and buttery quality to it and Rose Madder comes from a natural dye and is more of a liquid paint. Paints have very individual qualities but the only reason for this is the medium that is added.
Commonly, artists may use turpentine to thin oil paint however, turps evaporates and leaves nothing for the colour to bind to. Turpentine is not a medium and it shouldn’t be used to think oil paints. Linseed oil is the correct medium for this purpose, the colours don’t become transparent when using it and the paint binds easily. The thinner the paint you want, the more Linseed Oil you would add. Mediums give you the potential to change the consistency of paint by adding them to it. You can also use mediums to increase the drying time of oil paint.
To make oil paint, you use Linseed oil, you use it to extend oil paint also. Refined Linseed oil will slow dow the drying time when using oils. Stand oil is exactly the same material as linseed oil, its a lot thicker in consistency and because it is thicker, it tend to get rid of brush marks when it is mixed with paint and applied. If making acrylic paint, you wouldn’t use Linseed oil, you’d use an acrylic medium and copolymer, a colourless acrylic paint with pigment. This mixture should then b ground together as if you don’t bits of pigment will be floating in it. However, this could be a desirable effect to use within your work. If you extend acrylic colours with PVA Homopolymer the paint will become glossy and plasticky. You can add a matting agent to if afterwards if you want to get rid of the glossy effect. The paint will be a lot thinner when you add copolymer but you can thicken it uo with copolymetric thickener. The more you add the thicker it gets but if you put too much it will solidify. It is really interesting to me that making and using mediums is like baking and following a recipe. If you wanted your paint to be thick, chalky and dry you could add powders to it. With Acrylic, you could paint a thicker mixture of paint and powder on and it would be dry and ready to work with in just 30 minutes. Acrylic paint is a glue, if you were using it with collage, it would stick the collage material to the painting. Acrylic is a lot less harmful than oil paint. Oil materials involve solvents and chemicals, also acrylic paint has a greater rang of consistencies. For example, you cannot make matt oil paint. The possibilities are greater with acrylic but oil paint is still favoured.
Acrylic didn’t used to be very permanent when it first came out, it cracked and the colour often faded over time. Colour Field artists were given acrylic paint to experiment with and started creating new ways of applying large expanses of colour like pouring it onto the canvas.
Now acrylic is a lot better and almost on parr with oils. Oil Paint comes in many different grades. The difference between student grade oil paint and an artist quality paint is that there is more pigment in artist quality paint and it contains real pigment where as student paints tend to be coloured with dye. I didn’t realise until undertaking this workshop that paint can carry a safety warning. Naples Yellow is like arsenic, it is highly poisonous. In student quality paint, there is no real Naples yellow pigment so its safe, but artists quality is toxic and does contain it. The reason you would use artists quality paint is usually if you were adding mediums to it, you would get more mileage out of it and the colour would still be rich even though mediums have been added.
Mediums and Varnish being different is a myth. Mediums and varnishes are the same material. If you are putting the material into paint it is known as a medium. If you are painting it on top of a painting it is known as a varnish. The way the material is used affects its name, not the material itself. A typical medium make up is 1 portion of oil, 1 portion of varnish and 4 portions of turps. You can obtain varnish in crystal form. It comes from a tree and is what you make damar varnish from. You would put a crystal in a cloth bag, hang it in a jar and fill the jar with turps. Damar varnish is a finishing varnish. Years ago, artists thought that the surface of a painting should be even and covered it in varnish to bring the painting to life. The disadvantage of all varnishes is that they eventually yellow and could turn a shade of brown. Industrial varnishes yellow even quicker. Varnish can also be used as a dryer. All paints conform to varying levels of transparency. If you make brighter colours transparent on a white background, they glow.
Wax is a painting medium, and allows you to work with incredibly thick paint, Microcrystalline wax is cold wax and is very thin but has a definite presence if used within art work. Hot wax makes an incredibly thick paint when oil paint is added to it. This can be seen in the work of Jasper Johns.
Wax has a quality that is unlike oil and acrylic, it is sort of in-between. Egyptians used it to bind the painting they did onto caskets. Wax painting holds every single mark of the brush used to apply it. Another artist that has worked with wax is Terry Setch, he uses buckets of it and embeds things within the wax.
Layering paint is an interesting idea. Painting one colour on top of another colour makes a third colour. In Rembrandt’s work. There are about 30 layers of slightly different colours, creating a new colour every time. Landscape Painters used layering to produce greens back when they were inaccessible. It is very difficult to describe the amalgams of colour that are created through layering. The combinations of glazes can be incredibly complex or incredibly simple. You can use layering and glazing to modify a colour. If a colour has become too cold, yu can make it warmer by applying a thin yellow glaze and vice versa, if it has become to warm you could use a thin blue glaze to cool it down.
You could mix up a heavy dark colour of glaze and use a soft cloth to take glaze away and allow the white behind it (as long as you had used a white ground) to come through. you can reveal the underneath colour and build up highlights and shadows this way within a painting. Rather than adding white, you are creating volumetric space. Layering glazes creates volumetric colour and depth.
Today there are many new mediums that are ready-made like synthetic resins. Liquin is an example. Spectra-Gel means you can put a glaze over something with thin, minimal colour, but with an incredibly thick paint consistency. The medium itself has a jelly like consistency and makes thick paint dry a lot quicker. Alcaflow is treacle in consistency amd tends to get rid of brush marks. Spectraflow is a thinner version of spectra gel. Spectra gel responds to friction, if you used a palette knife to apply it, it can flatten out if you over work it. Synthetic resins are much more prone to yellowing than traditional varnishes. You wouldn’t use synthetic resins as finishing varnishes.
Under taking this workshop has made me want to get samples of mediums and just have a little play with them and investigate how they change paint. I am going to experiment with how using a ground changes the end result of a painting and I will also experiment with how mediums can effect end results of pieces too. I came back from the workshop with a Jar of acrylic co-polymer to play around with as a starting point.