Why and How to Use Watercolor Mediums

Watercolor using Distilled water and Mediums 

  So with watercolor painting for some reason there is a lot of misinformation out there and other information that is completely lacking. Three of the most misunderstood subjects is using watercolor mediums and the use of distilled water vs. tap water. Let’s start with using distilled water to thin your paints. I have heard the rumors that using distilled water is superior to using tap water since I began watercolor painting back in high school. I have continued to hear it over the 20 or so years since then. I finally broke down to experiment with the possibilities of using distilled water. First off distilled water is slightly more acidic than tap water the higher ph could potentially be detrimental to your watercolor paper. That not withstanding I experimented using distilled water on different papers hot pressed, cold pressed, and rough watercolor paper. I also used distilled water in several watercolor painting techniques including gradient washes, flat washes,wet in wet, and wet into semi-wet and so forth. The verdict is there is no difference between tap water and distilled water. In fact distilled water didn’t perform as well as tap water. So in watercolor painting tap water is just fine. Let’s move on to watercolor mediums what they are for and how to use them.

Watercolor Mediums

Why and How to Use them Gum Arabic

Most watercolors contain a portion of gum arabic. It has the consistency of honey or light corn syrup it is used as a binder for watercolor paints. As a medium gum arabic increases the gloss and transparency of watercolors. Gum Arabic also helps slow down the drying time of paint giving you more time to work with you washes.

How to Use it:

Never use gum arabic straight out of the bottle. Always use it with water. At the very least use a small water resevoir with 8 oz water about 20 drops of Gum arabic. I also will sometimes use Gum arabic in my main painting water. Then you just use your water the same as you would if it didn’t have gum arabic. Something to be aware of if you use gum arabic your paint will lift off the paper more easily,so if you plan to use several layers of colors over other colors don’t use gum arabic.

Ox Gall Liquid

Ox gall increases the wetting properties and flow of watercolors with a few drops to your painting water. The colors will soften and blend together easier. The medium can be useful for ‘marbling’ or creating textures. It will also set your colors into the paper and make them harder to lift. If you want to create paintings with several color layers ox gall is the way to go.

How to Use it:

Using about 8 oz of water add 10 drops ox gall liquid. Use the medium to wet the paper for wet into wet or wet into semi wet techniques painting techniques.

17 thoughts on “Why and How to Use Watercolor Mediums”

  1. Do you have any information on gel mediums to mix with water before using either watercolour or gouache? I’m going to the Antarctic and have been told a gel medium is useful. Many thanks

  2. Imajean Specklemier

    I just wanted to add to your discussion of tap vs distilled water. Unlike you I don’t think I’ve ever known any artist to say that using distilled is superior in as far as how it makes their artwork better or worse. The only reason I’ve heard to use distilled over tap is to avoid mold on the palette. This especially true when the watercolors contain honey. Some home tap water (and/or old piping systems) contain forms of bacteria not harmful to humans, but that interact with the honey contributing to the formation of mold. Apparently the distillation process kills the bacteria… I doubt I said anything you anything you didn’t already know!

    1. I appreciate you pointing this out. I believe it helps forward the discussion. My palette is flat without color reservoirs so my colors dry out in few hours instead of being wet for days so I never have personally had problems with mold. I do however, know people that paint in watercolor every day using a palette with paint reservoirs and the colors are always wet or moist and so I have seen mold grow when this is the case. I was unaware that distilled water helped thank you for the tip.

    2. It also depends on the tap water in your area. Where I live in Florida, there is a something that turns sidewalks and streets rust red from outdoor sprinkling with tap water (we installed a well for this purpose to avoid the discoloration). Must be iron? Anyway, it makes me leery of using it in mixing my ceramic glazes. And equally, for any water used in painting.

  3. Hi,
    I find this thread very helpful.
    I’ll be moving to the Middle East soon and I’m concerned about drying times when living in the desert. I would like to know what mediums can I try to slow down drying times. Would gum arabic or ox gall help?
    I would appreciate any feedback on this regard 😉
    Thank you very much!

    1. Hi there! I believe Kevin covered both of those mediums in another question above. Looks like they would but have very different properties so I’d read it if I were you. Good luck!

    1. There are a couple of places online like JerrysArtarama.com or Utrechutrechtart.com, dickblick.com as well as many other online art supply companies. Winsor and Newton make gum arabic for watercolorists to buy and use with water as a medium. You will also be able to find ox gall as well. I hope that helps.

  4. Good for you for experimenting. I’d suggest repeating the experiment with hard water; adding Epsom salts to the water will make it harder.

  5. i have nothing to add to any comments but just wanted to say thank you to all the people who answered questions and posted comments. i came here to find out how to make my watercolors shine a little…when using my paints the less water i use the glossier they dry but i absolutely love metallica so i bought a set of mica powders and add a little to my semi moist paints instead of buying a whole metallic set, but this takes the gloss out of my dried paints so i was searching for a solution. i’ve looked for quite sometime and this thread has been the most helpful and i just wanted to say thank you to ya’ll for the wealth of info that i acquired…in so very very new to this and really need all the help i can get. i’ve never taken any classes and have no artsy abilities but yet i love to paint (it’s a curse and highly embarrassing how truly bad i am) but thanks again and keep up the posts and added info it really is very helpful!!

  6. The issue pertaining to water is that there is bacteria in tap water. My thinking is that water should be boiled and not distilled as distilling does nothing to kill the bacteria. Boiled water is considered to be sterile. No bacteria. In conservation framing they boil the water to make wheat paste because the bacteria will degrade the art over time. I feel that this should also be a consideration when painting. The results of using tsp water may not show up for many years. It may cause mold in your palette.

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