Making —Pyrrole Red watercolour paint


Current procedure — last updated 30. August 2022

  1. Mix the watercolour paste
    1. Wear a mask. Go outdoors - this can be very messy.
      Pour the medium into the stainless steel container first.
    2. Measure out the powdered pigment.
      Add about a third of it to the Blender Ball, and then top off with about 250ml of medium.
      Seal it up and shake back and forth 60 times.
      Repeat twice more, and then pour in the remaining medium and shake to roughly rinse.
    3. Start dispersing, using a dispersion disc in a drill press.
    4. Cover the bowl while dispersing to limit the dust.
  2. Mill the paste
    1. Set both rollers to 6mil.
    2. Prepare a large bowl and a hopper to use. Find a stand to raise up the bowl to catch the paint to reduce splashing.
    3. Use a nail brush and water to clean the rollers at the end of the first runs.
    4. Put through the mill 8 times.
    5. Test for grind at the end of run #4, #6, and #8.
    6. At the start of run #7, add one drop of clove oil for 250ml of total medium (100ml mix = 4-5 drops) Add the oil to the paste on the slow rollers, rather than in a bowl on in the hopper.
  3. Package into pans
    1. Arrange the 350ish empty 2ml half-pans into rows on a cookie sheet
    2. Fill the pans to the top with a pipette set to 2.3ml
    3. Allow to dry, and then top off
    4. Allow to dry, and then package into wax paper bags

Drapak’s manufacturing notes

26. August 2023 - 1 batch of 40g pigment: 300ml medium
Pr254 powdered Pyrrole red pigment: 40 grams × $0.240/g = $9.60
Watercolour medium 300ml × $25.41/1000ml = $7.62
Number of pans filled 360 pans × $0.08/pan Cost of new pans = $4.80
Total for materials = $22.02 Material cost/pan = $0.16
Time to mix 20 minutes
Time for pre-dispersion 10 minutes
Time to mill 60 minutes
Time to dispense 40 minutes
Total time 130 minutes
Number of runs 10
Final grind size 7.5-10µm
Time spent per pan 0.93 minutes × labour rate $0.48/min= $0.45
Total cost/pan = $0.61

This worked very well. I added quite a bit more water than in the first batch, and this made it easier to dispense. The pigment does want to resist water, but then it swells like crazy. The pans may need a third filling. So vibrant, though!

30. August 2022 - 1 batch of 75g pigment: 500ml medium
Pr254 powdered Pyrrole red pigment: 75 grams × $0.240/g = $17.98
Watercolour medium 500ml × $23.09/1000ml = $11.55
Number of pans filled 205 pans × $0.08/pan Cost of pans = $16.40
Total for materials = $45.93 Material cost/pan = $0.224
Time to mix 22 minutes
Time for pre-dispersion 30 minutes
Time to mill 180 minutes
Time to dispense 30 minutes
Total time 232 minutes
Number of runs 10
Final grind size 7-15µm
Time spent per pan 1.13 minutes × labour rate $0.445/min= $0.504
Total cost/pan = $0.728

This was an interesting pigment. It wet quite well, and did not make much mess. It might even be OK to mix indoors.

I did 10 runs on the mill, but I am not sure if the 9th and 10th runs truly helped.

The material was somewhat granular at first, and tended to block up the rollers during the first few runs. Adding a little water helped in the early runs.

Later on, it got very very smooth, and was a real joy to mill. It has an opacity that looks great on the machine.

Dispensing was still irritating. The pump works so much differently with paste than water. And it is still not pushing out things rapidly. It about an hour to dispense the paste. I may have to add an option to change the speed of dispensing in the menu. I am even wondering if I should shift back to the old stepper drive. It was loud but fast.