To get the hang of gum printing it may be a good idea to print tone scales with the intended pigments. This print will be a useful reference when choosing colors and determining exposures and tone rendering.
Here is another try to achieve results similar to the previous gum test, using only three print layers.
Three stock pigments were made and used diluted for the sensitizer:
1. Maimeri Ivory Black 1 g + gum arabic (14 Baume) 20 ml
2. Maimeri Prussian Blue 1 g + gum arabic 20 ml
3. Maimeri Alizarin Carmine 1 g + gum arabic 20 ml
Coating was made with a foam brush, then evened out with a Hake brush.
Paper was Somerset 200g, preshrinked.
Sizing: Gum + dichromate + water, 1+1+1 parts, exposed 4 min. with Osram Ultra-Vitalux from one meter, washed for 60 min.
Pigment: 1 part Ivory Black Stock + 1 part gum + 2 parts dichromate
Exposure: 18 min.
Development: 30 min.
Pigment: 1 part Prussian Blue Stock + 1 part gum + 2 parts dichromate
Exposure: 6 min.
Development: 70 min.
Pigment: 1,5 parts Alizarin Carmine Stock + 0,5 parts gum + 2 parts dichromate
Exposure: 10 min.
Development: 24 min.
Clearing: Potassium disulfite 5% 2 min.