Making —Watercolour medium

Ingredients (roughly $6/250mL)

Tools

Current procedure (last updated 12. August 2022)

  1. Add enough water to the double boiler to just less than the level of the pot
  2. Turn on the stove to one mark less than medium
  3. Measure out one portion of honey into the bowl
  4. Then add three portions of hot water into the bowl, which cleans out the honey from the cup
  5. Measure out one portion of glycerine into the bowl
  6. Measure out three portions of hot water, cleaning the glycerine out from the cup
  7. Add two drops of defoamer - expect this to be gooey!
  8. Measure out two portions of powdered gum arabic into a second mixing bowl
  9. Sprinkle the gum arabic to the pot, stirring with a whisk as you go
  10. Expect there to be some clumping. Whisk by the edge of the bowl to break up clumps of gum arabic while sprinkling. Don’t worry about being too perfect, though!
  11. Once all the gum arabic has been added, whisk to break up all but the smallest clumps
  12. Put aside and cover the pot with a cloth
  13. Clean up the kitchen properly, because you are a good human. Leave it better than you found it.

Instructions and notes from Kremer Pigment

See also: Recipe: Watercolor Medium and Recipe: Watercolor based on Gum Arabic

Watercolour medium is the material that you add coloured pigment to in order to make watercolour paint. It helps the paint stick to the paper, and increases its colour depth and handling. Making watercolour medium is pretty simple. This is the recipe that I found works best for me. It provides the best balance of colour depth, with great wetability and limited crazing.

Everything starts at the stove. We start with a makeshift double boiler made out of a pot of water with a mixing bowl stuck on top. We keep the temperature in the middle between low and medium. The idea is to keep the mixing bowl hot to make it easier to dissolve the gum arabic without boiling the water.

Start with 6 parts of water poured into the top of the double boiler. Measure out your 2 parts of gum arabic powder by volume. Sprinkle in the gum arabic powder while stirring with a whisk. This will dissolve the gum arabic much faster than using a spoon and stirring. However, it will cause some foaming. This is a nuisance, and if you have some defoaming agent, a couple of drops will solve the problem. Keep sprinkling and stirring until the gum arabic is dissolved. This will take a while: imagine all the money you are saving while you do this.

Then measure out one part of glycerine and one part of liquid honey and pour this into the mix. Whisk gently to stir things together, and then take the double boiler off the heat and let the mixing bowl cool. If your medium is too hot, it may deform PET bottles. Once the medium is reasonably cool, I pour them into bottles that are ready to mix with pigment paste.

Drapak’s manufacturing notes

10. August 2022 - 2 batches of 1000ml (125ml portions)
Gum Arabic 150 grams × $0.045/g = $6.75
Honey 125 ml × $0.012/ml = $1.50
Glycerine 125 ml × $0.040/ml = $5.05
Water 750 ml
Total for materials = $13.30
Time to mix 22 minutes × labour rate $0.445/min= $9.79
Total cost/1000ml batch = $23.09 Cost/ml = $0.023

Again, a standard mix, but a little faster than normal! 😊

5. August 2022 - 2 batches of 1000ml (125ml portions)
Gum Arabic 150 grams × $0.045/g = $6.75
Honey 125 ml × $0.012/ml = $1.50
Glycerine 125 ml × $0.036/ml = $4.50
Water 750 ml
Total for materials = $12.75
Time to mix 30 minutes × labour rate $0.445/min= $13.35
Total cost/1000ml batch = $26.10 Cost/ml = $0.026

I think it is time to establish this as a standard procedure.

1. August 2022 - 2 batches of 1000ml (125ml portions)
Gum Arabic 150 grams × $0.045/g = $6.75
Honey 125 ml × $0.012/ml = $1.50
Glycerine 125 ml × $0.036/ml = $4.50
Water 750 ml
Total for materials = $12.75
Time to mix 30 minutes × labour rate $0.445/min= $13.35
Total cost/1000ml batch = $26.10 Cost/ml = $0.026

Very simple. Nothing new to report. This procedure is becoming straightforward.

1. August 2022 - 2 batches of 1000ml (125ml portions)
Gum Arabic 150 grams × $0.045/g = $6.75
Honey 125 ml × $0.012/ml = $1.50
Glycerine 125 ml × $0.036/ml = $4.50
Water 750 ml
Total for materials = $12.75
Time to mix 30 minutes × labour rate $0.445/min= $13.35
Total cost/1000ml batch = $26.10 Cost/ml = $0.026

Very simple. Nothing new to report. This procedure is becoming straightforward.

21. July 2022 - 2 @ 1000ml batches
Gum Arabic 150 grams × $0.045/g = $6.75
Honey 125 ml × $0.012/ml = $1.50
Glycerine 125 ml × $0.041/ml = $5.13
Total for materials = $13.38
Time to mix 30 minutes × labour rate $0.445/min= $13.35
Total cost/1000ml batch = $26.73 Cost/ml = $0.027

This went quite well. I bought some silicone lids for the mixing containers to cover the medium. But one ripped on the first try. Boo! So I just have them on there loosely.

The cost of glycerine has gone up. And I forgot to add GST to the honey. Or maybe I didn't. I have to check the receipt next time. In any case, the cost has gone up. This will obviously increase the cost of the pans a little.

I am still looking to reduce the labour. Alison found a double boiler from Ikea that I will buy to test. So much of the time comes from clean-up and setup. Larger batches could help with this.

17. July 2022 - ½ cup portions = 4 cups @ two batches

150g gum arabic ($5.88) + 125mL glycerine ($4.48) + 125mL honey ($1.50) = $11.86 + 30 min per batch

No problems. I decided to weigh out the gum arabic using my postal scale. I made two batches in order to be more efficient with time due to reduced clean up. This was my cleanest batch yet. I weighed the gum arabic in a bowl, and this did not cause as much powder to fly when I shook the paint out. Whisking is the way!

17. March 2022 - ½ cup portions = 4 cups

140g gum arabic ($5.49) + 125mL glycerine ($4.48) + 125mL honey ($1.50) = $11.47 per batch

No problems. I shook the powder from the stainless steel cup, but it all still took less than 30 mins, including cleanup. I have started adding the clove oil downstairs. I have started adding the gum arabic more aggressively because it dissolves relatively quickly when I whisk the lumps. The few remaining lumps continue to dissolve when I put the medium to the side to cool.

12. March 2022 - ½ cup portions = 4 cups

140g gum arabic ($5.49) + 125mL glycerine ($4.48) + 125mL honey ($1.50) = $11.47 per batch

No problems. I forgot to shake the powder from the stainless steel cup, but it all still took less than 30 mins, including cleanup.

However, the clove oil was too strong. I am reducing the amount to one drop per cup.

28. February 2022 -

½ cup portions = 4 cups - 150g of gum arabic ($5.88) + 125mL glycerine ($4.48) = $10.36 per batch

This was a straightforward mix - no problems. I shook the gum arabic from the stainless steel cup and that seemed to keep my fingers happier!

20. February 2022 -

½ cup portions = 4 cups - 130g of gum arabic ($5.10) + 125mL glycerine ($4.48) = $9.58 per batch

I mixed another batch using ½ cup portions. This time, I increased the heat to one mark less than medium. I tried using a tea strainer to powder the gum arabic better, but it did not work. The extra heat certainly helped, and the process was a little faster, despite the delay from trying to use the strainer. It took just a little less than ½ an hour, including cleanup. I put on the fume hood light and fan, and this made the experience a little nicer. I am getting cleaner.

19. February 2022

I mixed another batch using ½ cup portions.

This time I filled the double boiler up to nearly touch the bottom of the top pot. It took much less time: ½ an hour. I used the normal method of slowly stirring the powder in with a whisk. I did not add any clove oil yet. I left it out overnight with a cloth on it, and in the morning the final small lumps were dissolved beautifully.

13. February 2022

Mixed a batch using ½ cup portions. It took about an hour and filled the double-boiler just enough to be able to mix without a mess. I added two biggish drops of defoaming agent, which kept things under control. I also added fifteen shakes of clove oil, which was enough to stink up the whole house.

To do: Stick with ½ cup portions, play a podcast, and use about half the amount of clove oil. Perhaps add at the end.