Ida Mager

Watercolour paint
Watercolour paint is genuine paint. Like acrylics and oils it is finely ground pigment with a binder. In acrylics the base is a polymer, in oils it is linseed oil and gum turpentine, in watercolour paint it is gum arabic next to some more ingredients.
 Gouache also contains gum arabic, with calcium carbonate added to make it opaque. Watercolour paint is transparent. Unlike acrylics and oils you cannot cover a dark colour with a light one. That’s why in watercolour we usually work from light to dark tones. Where colours overlap fine mixtures appear, like in coloured glass. Gouache is very useful for opaque colour accents in a watercolour.

Tubes or pans?
Half pans come mainly in little boxes and are suited for traveling, sketching on location and small watercolour paintings. If bigger brushes and larger sheets of paper are required, tubes are needed. You sqeeze out as much paint as you need; dried paint on the palette can be re-wet and used again, although it may become crumbly after a while. Similarly you can re-use gouache. Watercolour remains re-soluble when the painting is dry, which enables you to scrub away or change some parts, but also makes it vulnerable to moist and dirt. That’s why they need to be mounted under glass or stored away humid-proof. You may want to spray it with a thin coat of watercolour protecting spray.

Are they lightfast?  
Paint will not fade as fast as ink does. Modern watercolour paint is quite lightfast; mounted under glass the paintings can be hung in neutral daylight, but avoid glaring sunlight.