What is blocking in?

Blocking in is a process by which we begin by adding colour to each part of our picture so that every area has a single layer of flat colour. Flat colour is the term used for an area of colour that is unshaded and of a plain, smooth texture. So, in the initial stage our painting may have plain blue for the sky, green for the foliage and brown for a tree trunk. Thereafter we will modify these base colours.

Blocking in has the advantage of establishing all our main colours from the outset so each part of the painting progresses at the same rate. As we add colours and tones, we can judge them against others already in the painting, not against stark white as in last month’s image. No part of the painting is completed significantly earlier than the others.

How do I modify a colour?

There are numerous ways to do this: scumbling, dry brushing, stencilling, glazing, sponging, spattering among many others.

Modifying gives an appearance to an area of paint that could not be achieved with a single layer alone. We can modify a colour either by using contrasting tones or colours, or by using a very similar colour so the difference is very subtle. Try using the same method for different colours and tones to see how those differences affect the results.


Scumbling (see example below) is an effect where a similar or contrasting opaque colour is rubbed over the initial colour. Scumbling is excellent for cloudy skies, as the brushmarks are soft edged. It’s also useful for softening a background colour, perhaps for a portrait, when you want an interesting, but muted colour.

Take neat, or slightly diluted, paint on your brush, wipe off a little on a rag or paper then gently rub the remaining colour over your surface. Old brushes are especially useful for this purpose. Do not cover the surface completely. Your aim is to let some of the initial colour show.

In this example I used a single colour over a dry base. Alternatively, you could use two or more colours and scumble them together. Try it!

Dry brush

Similar to scumbling, dry-brush work is when you use neat paint, wipe most of it from your brush then gently pull the remaining colour across the surface. Dry brushing works best over a textured surface, as the paint catches the top ridges of the surface, but any troughs remain as the underlying colour.


Glazing is when a thin layer of transparent colour is applied over the underlying colour.

Jackie Garner will be exploring more techniques in the rest of her 2021 acrylic painting series in Leisure Painter. Subscribe to ensure you don’t miss a single article.

Demonstration: Summer Afternoon