Ingredients
- 150 part dry powdered pigment by volume Pyrolle Red Deep Pr254 from Kama Pigments
- 1000ml of watercolour medium
- 1/8 part extra water
- PPE: mask, gloves, and apron
- A measuring cup
- A digital scale
- A stainless steel bowl (1500ml+)
- A stainless steel hopper (1500ml+)
- 28oz Blender Ball protein shake mixer
- Drill press with dispersion disc
- A three roll mill
- Small watercolour half-pans
Current procedure — last updated 30. August 2022
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Mix the watercolour paste
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Wear a mask. Go outdoors - this can be very messy.
Pour the medium into the stainless steel container first.
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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. - Start dispersing, using a dispersion disc in a drill press.
- Cover the bowl while dispersing to limit the dust.
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Wear a mask. Go outdoors - this can be very messy.
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Mill the paste
- Set both rollers to 6mil.
- Prepare a large bowl and a hopper to use. Find a stand to raise up the bowl to catch the paint to reduce splashing.
- Use a nail brush and water to clean the rollers at the end of the first runs.
- Put through the mill 8 times.
- Test for grind at the end of run #4, #6, and #8.
- 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.
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Package into pans
- Arrange the 350ish empty 2ml half-pans into rows on a cookie sheet
- Fill the pans to the top with a pipette set to 2.3ml
- Allow to dry, and then top off
- 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.