Greg Howard is a professional fine artist specialising in atmospheric, dramatic landscapes in watercolour & soft pastel. His work can be found in collections worldwide and he is a sought after tutor due to his easy going, informative no nonsense approach to the medium.

This was written  particularly to help newer watercolour artists that may be starting out or indeed for artists that have been painting a while and are unsure about the proper use and application of the various watercolour mediums available.


The world of watercolour mediums can be confusing and it might seem like sacrilege to talk about mixing watercolour mediums and additives with watercolour paints. It is, after all the purest of paint types, relying on its translucency to allow the whiteness of the watercolour paper to glow through. However, there are several traditional mediums and additives which can make life easier for the watercolour artist and add new dimensions to their paintings.


Please remember as with a great many things in life - less is more! These products can greatly enhance your paintings when used correctly and sparingly but they can also ruin a painting when overused. It is important to remember at all times that these products are meant to compliment existing techniques and not act as a substitute for them.


There will be purists out there that will object loudly saying that if you can’t produce all the effects you need with paint alone you shouldn’t be painting anyway. To them I say - Rubbish. Watercolour mediums were made for one reason and that is to compliment artists existing skills they do not and will not in any way replace good painting practise. So if you are looking to watercolour mediums to help you achieve miracles you will be sadly disappointed. With that in mind let us continue.


Masking Fluid

Masking fluid is a latex rubber solution for brushing or drawing onto your paper that dries yellow so that you can see where it has been applied. Once dry you can paint over the masked area, which then resists the paint. After the paint has dried, remove the masking fluid gently with a clean finger or a putty eraser. The white area revealed can be left as a highlight or tinted as desired. There are various ways to apply the fluid e.g.; brush, colour-shaper, pen, credit card, cotton bud, etc. Please remember if you intend on using one of your brushes make sure it’s an old one and that you wash it out immediately. Masking fluid starts drying very quickly and can ruin brushes. A good tip here is to apply some washing up liquid to the bristles before you start then wash it out immediately after. This puts a protective coating on your brush that goes some way to protecting the bristles. Masking fluid is ideal for reserving highlights and intricate shapes (window and door frames, tree trunks, thin grasses, etc.) However, use it with discretion!

Masking fluid is available in a number of forms. There is general purpose Art masking fluid. Permanent masking fluid is well, permanent and cannot be removed once applied and colourless fluid is exactly the same as general purpose art masking fluid except it is specially designed for soft-sized papers where there is a higher risk of staining occurring.


Iridescent Medium

Add to transparent colours to give a pearlescent (*) or glitter like effect. It can be mixed with the colour or applied over a dry wash and is most effective with translucent colours and over dark backgrounds.

[(*)-pearlescent - having a play of lustrous rainbow colours; “an iridescent oil slick”; “nacreous (or pearlescent) clouds looking like mother-of-pearl”; “a milky opalescent (or opaline) lustre”]


Watercolour Texture medium

Texture medium is used to produce a textured finish for watercolours, this medium can be applied directly onto the paper, or mixed with watercolours first. The solution contains fine particles that help give the impression of depth and more structure to watercolour paintings and to emphasise areas of naturally occurring texture such as sandy beaches, bark and other such naturally occurring textures. It can be used with multiple washes and can be mixed with colours or applied directly to paper.


Gum Arabic

Most watercolour paints contain a proportion of gum Arabic. It is a soluble gum (remember the old bottles of light brown office gum?) which when used on its own increases the gloss and transparency of a watercolour. Gum Arabic slows down the drying time of paint which can be very useful if you are painting plein-air during the summer months. You add the medium to watercolour in small amounts until the desired level of transparency is achieved. It may be thinned with water. Gum Arabic should not be used straight from the bottle as thick films can be brittle so remember to always thin with water. The medium can also be added to your jar of dipping water.


Watercolour Blending Medium

Blending medium when mixed with watercolour slows the drying time of colours allowing more time for blending. It is also ideal in very warm climates or the studio when you have the central heating on and can be used undiluted with watercolours to maximize your drying time. You can actually get the same effect by adding a little alcohol to your water. This also works in very cold outdoor situations, where mixing plain water with watercolour paint can actually freeze it on the paper. When dry further washes can also be applied.


Granulation Paint Medium

Watercolour artists have always recognised that the use of certain colours such as viridian or French ultramarine can produce a wonderful granulating effect as the colour settles and dries on the paper especially when using a rough surfaced paper(this can be quite disconcerting for newer artists that don’t understand the properties of various pigments). This effect can when used properly help produce wonderful textures and depth in a painting. Granulation medium encourages all watercolour pigments to granulate producing this mottled or granular appearance with colours which usually give a smooth wash. For maximum effect, dilute colours with medium alone, it is resoluble simply by rewetting.


Lifting Paint Medium

Lifting preparation medium is applied to the paper and allowed to dry before applying paint, this enables you to lift off colours for highlights etc. more easily. This makes it Ideal for beginners to more easily correct mistakes which may help them paint with a little more confidence. It allows dry washes, including staining colours, to be lifted from paper more easily, using a wet brush or sponge. Please remember that this medium must be applied to the paper and allowed to dry before applying paint.


Ox Gall Liquid

Ox gall (clarified) is a pale colourless liquid that increases the wetting properties and flow of watercolours on the paper with a few drops added to your water pot. This is very useful for ‘marbling’ techniques on hot pressed paper. It can also be used on hard sized papers to reduce surface tension. If a paper is resisting taking a wash leave it to dry then cover with diluted Ox Gall, when the solution is dry you can then paint as normal.

Watercolour Mediums
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Love this OR hate it? Let me know in the comments!…


  1. Wini

    So useful for the beginner! Thank you Wini

    • Greg Howard

      My pleasure, glad you found it helpful! 😉👍


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