Underpainting

I am sure like some of you, underpainting wasn't something I learnt in education. It is a technique I learnt through watching other artists on social media sites and playing around with it myself. So what is underpainting? Underpainting dates back to the Renaissance and helps with laying out the composition and the values (tones), before adding the colour. It is often monochromatic. When using acrylic, underpainting also acts as a base layer, so after I have applied it, I get straight into overpainting the middle layers.

Underpainting can change the effect of the overpainting. For example, I have applied a pink tone under a bright blue sky to give it brightness. Using blue tones as an underpaint can give the painting a cool effect, which is great for snowy scenes. Furthermore, elements of the underpainting can be left uncovered, giving it depth and definition. For example, when painting a picture of a flower arrangement, I underpainted it in purple tones and left some edges of the foliage untouched, so the purple would radiate through.

Do I underpaint all my paintings? No, I don't, because I think it's good to experiment and it depends on what subject I am painting. However, the more I underpaint, the more I find this technique more powerful then I first thought. It helps me structure the compositions and understand the values (which is more important than colour). It's almost like teaching: underpainting is the planning stage, then you implement the colour, values and textures of the paint, and, hey presto, you have the impact of the product at the end.

Burnt sienna is my main go to colour for underpainting as it is an earth colour and is very natural. I have watched artists throw the underpaint colour onto their canvas and wipe off the excess. Others (like myself) are more accurate with their application. Some oil painters use acrylic as an underpaint before they apply their oils (note that you cannot put acrylic on top of oils). Nevertheless, you don't need to be flawless with your underpainting as it will be painted over.

If you haven't underpainted before, give it a go and practise it with various subjects and compositions. Have a look on YouTube or Instagram to see how other artists implement it too.

Here are some tips on underpainting:

• Study the reference photograph in detail. Which colours ping out at you? Which colours can you see if you start unpicking? Do you want the composition to feel cool, warm or earthy?

• Practise underpainting with different colours in a sketchbook. What happens if you use lilac tones under green leaf, burnt sienna under a woodland composition, phthalo blues under snow, raw umber under a bird, or a magenta under blue sky?

• Change the reference photograph to black and white, so it is easy to identify the different values.

• Practise painting tonal studies using either watercolour or acrylic. Use one colour and vary the tone. Remember if you are using watercolour, slowly build up the layers using a single, dilute colour, with a wet-on-dry technique.

• If you are using acrylic, change the paint to a watercolour consistency. Add a single dilute layer then as it dries, build up the layers in areas where the values are darker.

• Try different effects. Which works better for you?

Give it a go. Let me know what you discover.