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Making Watercolour Paint

Making watercolour paint at home, while more time-consuming than buying store-bought, is a rewarding and meditative process that many enjoy. It is something that anyone can do if they have the interest in time. This article is an attempt at demystifying the paintmaking process for beginners and the curious.

There is some investment needed to make watercolour paints at home, as you will need the right equipment and raw materials. KROMA sells all of the ingredients and most of the tools necessary to make watercolour paints. You can find them all here.

mulling quinacridone violet

INGREDIENTS IN WATERCOLOUR PAINTS

  • PIGMENT - Pigment is the core ingredient in watercolour paints. A wide variety of pigments are available, although some are more suited to watercolours than others. Each pigment has its own unique characteristics, will require a different amount of binder, and will create a slightly different texture of paint.
  • GUM ARABIC - Gum arabic acts as the binder for watercolour paints. Essentially a glue, the gum arabic fully encases the pigment, allowing it to adhere to surfaces with the use of water.
  • DISTILLED WATER - Pre-made gum arabic solutions are available, but it is more efficient and cost effective to make the solution yourself using distilled water. It is important to use distilled, rather than tap or spring water, as the minerals and impurities can impact the quality of the paint. Distilled water is generally available at large supermarkets or drug stores.
  • HONEY - Honey acts as the humectant for homemade watercolour paints, helping them to retain moisture and to re-wet nicely. It also increases the flexibility of the binder, as gum arabic can be quite brittle, and acts as a preservative. Assuming the watercolour produced is not binder-starved, honey will help prevent it from cracking in the pan.
  • GLYCERIN - Glycerin, like honey, is a humectant and plasticizer, helping the gum arabic to dissolve in water and store nicely. While honey and glycerin fill essentially the same role in the production of homemade watercolour paints, they seem to work best when used together.
  • CLOVE OIL - Aside from covering the slightly unpleasant smell of gum arabic, clove oil acts as a natural preservative, giving your homemade watercolour paints a longer shelf life without the risk of attracting yeasts or other microbes.

MATERIALS REQUIRED TO MAKE WATERCOLOUR PAINTS

  • GLASS SLAB - Essential to the home paintmaking process is a flat, nonporous surface on which to mix and mull. Traditionally, a mixing slab is made of stone. We like to use thick, glass plates because the materials can be easily removed with warm water.
  • GLASS MULLER - Equally as essential is the glass muller, a unique tool used to mix and refine your paints. The bulk of your paintmaking time will be spent mulling. A glass muller is an investment, and, unless you are a glass blower, there is no viable alternative to purchasing one.
  • PALETTE KNIFE - You will need a good palette knife to scrape and control the paint throughout the mulling and packaging process. There is some discussion among KROMA staff as to whether a metal or nylon palette knife is better - it really is a matter of personal preference. 
  • MEASURING SPOONS - To avoid contamination, it is a good idea to have a set of measuring spoons used only for paintmaking, never for food. These should be stainless steel and cleaned thoroughly after each use.
  • SQUEEZE BOTTLE OR ATOMIZER OF DISTILLED WATER - While an atomizer is preferred, such tools can be quite pricey. A squeeze bottle will suffice just fine.
  • RAG - We like to use paper towel, but reusable rags also work fine. Remember that whatever you use may end up stained.
  • BREATHING PROTECTION - When working with dry pigments, protection should always be worn to avoid inhalation. While a respirator is recommended, at the very least you should wear a particulate mask. These are available at any hardware store.
  • WATERCOLOUR PANS - Once you've made your paint, you'll need somewhere to store it! KROMA sells stainless steel watercolour pans. There are also plastic ones widely available. Or, for a more economical option, you can use clean bottle caps.

MAKING WATERCOLOUR BINDER

To make a watercolour binder, you must first make a gum arabic solution using 1 part gum arabic to 2 parts distilled water. Fully dissolving the gum arabic in the water can be tricky, but there are some strategies to help it along. The first is to use warm (but not hot) water to help the gum arabic dissolve. Use caution, as you don’t want to cook the gum arabic. The second strategy is to leave the solution overnight in the fridge, shaking occasionally to help any undissolved gum arabic along.

Once you have your gum arabic solution, combine 60ml with 1 tsp (5ml) glycerin, 1 tsp honey, and one drop of clove or eucalyptus oil in a jar (preferably glass) and stir well. This watercolour binder should see you through several rounds of paint making, and will last up to a year if kept refrigerated.

CHOOSING PIGMENTS

There are many, many pigments available on the market, and choosing which ones to use in paintmaking may seem like an overwhelming decision. If you’re having difficulty choosing which pigments to use, try starting with basic primary colours - benzi yellow, ultramarine blue, and quinacridone red. You can use these pigments not only to create beautiful single-pigment colours, but also to create stunning blends, particularly with the addition of zinc white.

For your first time making paint, we recommend starting with ultramarine blue, which, simply put, loves to be made into watercolour paint. While pigment to binder ratios vary, ultramarine blue uses a simple 1:1 ratio, incorporates well into the binder, and is a joy to mull. Benzi yellow and quinacridone red will give you some more trouble and use a 1:2 pigment to binder ratio, but create truly stunning transparent colours in the end.

MAKING WATERCOLOUR PAINT

Now that you’ve made your binder, assembled your materials, and chosen your pigments, you are ready to make paint!

To start off, you should be wearing a respirator or particulate mask to protect yourself from inhaling dry pigment powder. Next, measure out your dry pigment in the centre of your glass slab. We recommend starting with ½ tsp dry pigment to make about one half pan to one full pan of watercolour paint.

With the back of your measuring spoon, make a depression in the centre of your pigment pile, then add your binder. You may choose to add the binder in stages, or all at once. Choose whichever method suits you best. Each pigment will have a different pigment to binder ratio. If you are starting with ultramarine blue, the ratio is 1:1. For pigments with a very small particle size, you will need a 1:2 pigment to binder ratio. You can also adjust these ratios up to bring out the undertones in transparent colours.

Using your palette knife, work the pigment into the binder. Different pigments will take to the binder differently, depending on particle size and weight. Ultramarine blue works into the binder relatively easily, but smaller pigments like quinacridone red will require more massaging. We find it best to use the bottom of the palette knife to gently press the pigment into the binder. Once the pigment is fully mixed in with the binder, you can remove your respirator.


Once the pigment and binder are mixed, use the side of the palette knife to work the mixture back into a small pile in the centre of the glass slab, then begin the mulling process. Using your glass muller, gently work the paint in circles and figure eights. You will notice particles in the mulled paint at first. The object is to make as smooth a paint as possible, so you will usually find yourself scraping the paint back into the centre of the plate and then mulling it out several times. With ultramarine blue, this process is a relatively short one. With something like quinacridone red, however, it can take over an hour. You can’t over-mull paint.

In the case of pigments that take longer to mull, you may find you need to add some more distilled water to keep the paint fluid enough, so it’s handy to have an atomizer or squeeze bottle handy. You should also apply more pressure with tricky pigments. If you find the particles of pigment are still visible after several mulls, you can try adding a bit more binder.

If you are mixing pigments, particularly pigments of significantly different sizes and weights, the mulling process will take longer. It takes a few mulls for the colours to mix properly, so try to avoid adjusting the pigment ratios until you are sure the colour is fully developed.

Once you have a smooth paint with well-mixed colour, you can use your palette knife to scrape up the paint and transfer it into a pan. Pay attention to how it dries over the next few days. If it cracks, the paint is binder-starved, and you should use a higher binder to pigment ratio next time you make that colour.