Watercolours: Tube vs. Pan
Watercolour paints have been around for centuries with very little change. Originally starting as hard, brittle pans (or cakes) of colour, they were forever changed by W. Winsor and H. C. Newton. In the 1800s Winsor and Newton added glycerin to the pans which prevented the paint pans from being so brittle and also increased their solubility in water. The next change came when watercolours were produced in tubes. To allow the paint to stay moist within the tube, the pigments were mixed with glycerin, ox gall (bile from the gall bladder of a cow), and Gum Arabic (a natural substance that oozes from the Acacia tree). Most recently, ox gall has been replaced by a synthetic medium.
The difference between the two is more than likely a personal one. Give them both a try and see which you prefer.
§ Gum Arabic continues to be used as a medium for watercolours – as a glazing agent, when increased drying time is needed, or to enhance transparency. Gum Arabic also improves the way watercolours stick (or adhere) to a surface, and can also be used when mixing pigments.
§ A synthetic version of ox gall is used today to enhance the flow of watercolours and improve the absorption by paper.
§ Masking liquid (or Frisket) is used to prevent paint from being applied to specific areas of a painting. It is recommended that you do not use a sable brush to apply masking liquid as it can get embedded in the hairs, making your brush unusable. Use a synthetic brush instead, making sure it is moistened before dipping into the frisket. Easily erased with a natural rubber pick up, masking liquid does not damage the surface of your painting and leaves it ready to be painted. Be sure to let the painting dry completely before removing the Frisket – air drying is preferred over a blow dryer.
Quality in watercolours:
Artist-quality watercolours tend to contain higher-quality natural pigments (or synthetics) whereas student paints tend to have lower-quality genuine or synthetic pigments and have fillers to fatten up (or add bulk) to make their flow more like the professional-grade paint. Artist-quality watercolours are usually most expensive because of the higher quality ingredients – the best having genuine pigments such as rose madder genuine or lapis lazuli (used in ultramarine blue). As a note – when ‘hue’ appears on the label, the pigment is synthetic – such as in cobalt blue hue.
Be sure to select the best paint for your level of experience. Beginners might opt for the student quality watercolours as they tend to be more economical and progress to the professional or artist grade.