OIL PAINTING GUIDES
Oil painting tips: choosing and using your materials
People tend to be a bit afraid of oil painting, but it isn’t as complicated as you think and oils give a completely different (and I think nicer) character to a painting than acrylics. The biggest difference to get used to is the fact that your paints and all your equipment will need to be cleaned not in water but in turps (or their more modern equivalent). Here is a guide to choosing paint, canvas, and everything else you will need.
There are three options for oil painting surfaces: traditional stretched canvases, canvas board (or ‘canvas panel’) or canvas paper. Stretched canvasses, which are at least half an inch thick and often much thicker, are the most traditional option. Here the canvas is pulled tight around a timber frame and stapled to the sides or to the back. Stretched canvases can either be framed or can be placed straight on the wall for a more modern look. They can also be framed with ‘box frames’ where they are set loosely into a plain wooden sided frame.
Canvas board is made of canvas fabric stuck down to a thick board, and is a bit less expensive than a stretched canvas. It needs to be framed once you are finished. Canvas board is more rigid than stretched canvas, and you may prefer the feeling which is closer to painting on board (you can paint on smooth board if you like of course but will have to fully prepare, size and prime it first, which adds a lot of work to the procedure) It’s thin and portable so may be ideal to take outside if you want to paint from nature.
Canvas paper is very thick treated paper imprinted with a canvas texture, to which you can apply paint without causing warping or wrinkling. It isn’t advisable to complete an oil painting on canvas paper that you are intending to keep and display. It is really more for making preparatory sketches, and if you are a beginner in oils it might well be worth buying a pad of canvas paper to practice on. You can read more about these options on my oil paintings › page, or read my oil framing guide › for more information on how to display your canvas.
Priming your canvas
When buying a stretched canvas, you’ll have the choice between cotton or linen – if you like a smoother canvas then go for linen canvasses, which are a little more expensive but lovely to paint on. Linen fibres are more stable than cotton in the long term but harder to stretch quite as tight so may be more likely to sag. When buying a cheap cotton canvas however, there may be a little sagging present already, however the better brands (Daler-Rowney, Windsor & Newton, Reeves or Loxley) should all be fine. Canvasses (both stretched canvases and canvas board) are usually sold pre-primed. Before a canvas has oil paint applied to it, it MUST first be ‘sized’ (covered with a layer of glue, traditionally made from rabbit skin and now usually PVA) to seal the fibres and stop the oil paint from rotting them with its moisture and acidity. After that they need to be coated with a couple of priming layers mixed with the right amount of oil, which are then sanded smooth. Alternatively, a product called Acrylic Gesso is now commonly sold that can do both jobs in one, applied in several layers.
With a pre-primed canvas this is all done for you and the canvas has a nice bright white surface, ready for you to apply your paint. Check on the label if you aren’t sure – as you can see this one says it has been ‘triple primed with gesso’. Canvas ‘paper’ pads are all pre-primed and ready for you to work on too. Sometimes you may see linen canvases being sold un-primed – you’ll distinguish them as they are a natural brown colour. Beware of buying these unless you want to size them yourself with a tub of Acrylic Gesso.
Some canvas problems you may encounter…..
If you’ve been storing a canvas for a while you may find that it has loosened a little. In this case, before you start to paint you can tighten it a bit with ‘canvas keys’. These are the little wedges of wood which usually come in a plastic bag stapled to the back of your canvas, which you probably wondered what on earth to do with. (Ironically, you don’t always get them with the cheapest canvases, which are the ones which usually need tightening the most!) Anyway, wedge these ‘keys’ into the slots in the corners of the canvas, and tap them in lightly with a hammer taking care to tap evenly in each corner so as not to skew your canvas’s right-angles. This will tighten your canvas as the fabric tautens over the frame. If you can’t quite work out which way to put them in, there are plenty of videos on YouTube that will show you.
DENTS AND WRINKLES:
Canvases can become wrinkled if kept for a while or dented by a finger when being held or rested on. It’s easy to get these imperfections out: just turn the canvas upside down on the ironing board, on a piece of clean plain paper. With the iron on a cool heat (and preferably on ‘steam’ setting) quickly run it over the back of the canvas. This should re-tighten it instantly. I’ve even tried this with (dried) paint already applied to the canvas – I don’t think the heat will damage it if you do it quickly enough.
You’ll generally see a choice of several brands of oil paint in most art shops, varying somewhat in price. The difference between the prices usually reflects the amount of oil which the paints are mixed with within the tubes – you’ll find that the cheaper ranges may feel oilier and thinner as they have a greater proportion of oil to the pigment. It will also reflect the quality of the pigments used and how finely they are ground. I don’t like paint that feels too thin and oily so I use Windsor & Newton’s ‘Artists Oil Colour’ range, which is in the upper price range (although not the most expensive) but feels thick and buttery. Daler-Rowney’s ‘Georgian’ Range I find a little too thin, and Windsor & Newton’s ‘Winton’ series is really a student range and is even thinner.
If you want to paint REALLY thickly:
Buy some artists’ Impasto Medium – see more below. This can be mixed with any colour, and will add body to the paint allowing you to paint really thickly without your paint cracking. Your brushmarks will remain thick and stiff.
Keeping your costs down whilst using oil paints:
There are a number of ways to do this, and you’ll find more ideas on my oil painting handy hints page. Here are some basic suggestions though…. Firstly, make sure to keep the lids of your tubes clean. If they get caked with paint then air will start causing the paint to oxidize and dry up and you may end up wasting a tube if it isn’t one you use the most regularly. Secondly, don’t squeeze too much paint out onto your palette. I used to do this and you waste a lot of money that way. Put a tiny amount out initially – it goes further than you’ll be expecting. Lastly, Clingfilm (or Saranwrap) your palette overnight. This will stop air contacting with the paint, causing it to oxidize and dry out. Your colours will stay workable for much longer this way.
These are a relatively new product which I have recently tried – see this article. Essentially, a tube of water mixable oil paint is almost exactly the same combination of pigment and an oil binder – usually linseed or safflower – as a traditional oil paint. The only difference is that one end of the oil molecule has been altered so that it binds with water, as in a solution. The type of water soluble paints that you usually see in art shops is Windsor & Newton’s ‘Artisan’ range. This product would be great for people who are allergic to solvent mixers such as turps and spirits, or just those who want to try oil painting without the slight hassle of not being able to mix or clean the paints with water. The limitation would be that there is only currently a range of 40 different colours, less than a traditional range. However there is a good selection of thinners, spirits, oils and cleaners for water-soluble oil paints. There are also more expensive water mixable paints available online and you’ll find details in the article mentioned above.
Brushes are usually produced in different ranges which are suitable for being for used with either watercolour, acrylic paint or oil paint. Oil painting brushes are made from hog’s hair, which is strong enough for use with thick oil paint – thinner brushes made from sable wouldn’t last long when used with stiff oil paint and might not have the strength to manipulate it. For very fine brushes for doing detailing I have a couple of small synthetic brushes made for acrylic paint, but otherwise I use hog’s hair. Cheaper makes of brush are OK, you’ll probably just find that the hairs will fall out faster and they may be a little thicker. To extend the life of your brushes make sure never to leave them brush-end down in your jar of spirits! The brush tips will become bent and unusable. Always be sure to clean your paintbrushes very thoroughly as they won’t last long otherwise. See below on what to clean them with. Lastly, mix your paint on your palette using a palette knife where possible – don’t use your brushes.
Oil painting brushes usually come in two typical shapes – either rounded at the ends like these Windsor and Newton Winton Hog Brushes or square cut, which is good for applying paint in choppy brushstrokes. Remember that you aren’t limited to brushes for applying your paint! If you want to paint in a modern, thick impasto style you can apply your paint directly with a palette knife instead, like this selection by Windsor and Newton. This is usually used to mix your paint and clean your palette but artists since Van Gogh (and probably back to Rembrandt) have sometimes applied their paint with a knife rather than a brush.
MEDIUMS FOR DILUTING YOUR PAINT (and cleaning up)
It may be that you are happy with the paint at the consistency which it comes out of the tube. Probably however it will be a little thick and stiff for you to work with. You can’t dilute your paint by mixing it with water, but there are two options to achieve the consistency that you want. Probably you will want to use both of them at the same time for a satisfactory result. The first type are spirit-based such as Artist’s turpentine, or Artist’s ‘mineral spirits’ . Turpentine was the traditional spirit used for oil painting, but is somewhat toxic and can be absorbed through skin. Artist’s mineral spirits are fairly non-toxic (and won’t give you a headache!) There’s one disadvantage to diluting the paint with spirits which is that it also dilutes the balance between pigment and oils as they come mixed in the tube, so you may be left without enough oil in your mixture. This can cause the paint to appear very matt and dull and can even cause the paint to fall off as it ages. So to compensate, you’ll want to also use a few drops of oil.
Oils are the second way to soften and thin your paint. The most commonly used is Linseed Oil, but there is also Safflower, Hemp or Poppy Oil. Linseed oil is the most traditional but is a little yellowy, so for lighter colours you may prefer to use one of the other types. Be aware that oil paint is already mixed in its tubes with oil, so if you add a lot of extra oil your paint may appear overly shiny and glossy. But if you’ve already diluted your paint with a lot of spirits (see above) then it’s very important to add a few drops of oil to restore the oil and paint balance. Another advantage to adding a drop or two of these oils is that there are brands available which will speed up the drying of your oil paint. You can buy Drying Linseed Oil, or Drying Poppy Oil for the lighter colours. Another option which I like is Windsor & Newton’s ‘Liquin’ medium which speeds up the drying time of the paint and is non-yellowing so is suitable for any colour. You will also come across Stand Oil. Stand Oil is Linseed oil that has been thickened by heating. If you want to make your paint thick and oily – for a translucent glaze for instance with a little bit of paint added – Stand Oil will give you a thickness without strong brushmarks (if you actively want thick brush strokes, use some Impasto Medium) You can hear more about Stand oil and other mediums we have mentioned in this useful video.
cleaning your equipment using spirits
You can use Artist’s turpentine, or Artist’s ‘mineral spirits’ for cleaning brushes and palette knives, but this would be a bit expensive. You can also buy ‘Artists’ white spirit’ for cleaning up and this is a more economical option. You can buy regular white spirit from a DIY store which will be a lot cheaper but DO NOT use it to dilute your paint, as it will contain impurities which will slow the paint from drying. You can get quite a lot of paint off your equipment and yourself using water mixed with detergent., which is softer on the skin….but not necessarily all of it, in my experience. For your brushes, try giving them a short soak in some spirit and then washing them with detergent after first wiping them on some kitchen paper to get the worst excess of paint off them. Read more tips on cleaning up your equipment › to make it last longer.
Traditional wooden palettes are certainly the most environmentally friendly but they to be carefully cleaned with spirits to stop paint from drying hard onto them. This can be rather a difficult and messy job. Your other option is to use Tear-Off Palettes such as this one by Windsor and Newton, which come in A4 or A3 size and are much more convenient. At the end of a painting session you can just cover over your paint with some Clingfilm (Saran Wrap) to stop it becoming exposed to the air. When you are finally finished you can just tear off the sheet and throw it away. They are also easier to clean as they are more slippery than a wooden surface, so you can get a degree of re-use out of them by scraping off patches of un-needed or old paint and giving them a wipe with a cloth or piece of kitchen roll soaked in spirits.
If you want to varnish your oil painting to protect it, you’ll find a choice of matt or gloss varnish in an art shop. The important thing to know is that you must wait 6 months before varnishing an oil painting. This is because although the oil paint will appear dry to the touch after a week or two, it isn’t considered to be fully dry for many years as chemical changes continue to take place. After 6 months you can varnish safely without trapping moisture or risking significant contractions within the paint layer. Varnishing will help if you want your painting to be preserved over the centuries! I don’t consider it completely essential though and many people prefer the un-varnished matte look.
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