From the late 18th century through the 19th century, watercolours were used as the basic document from which collectible landscape or tourist engraving were developed.
Watercolour painting has the reputation of being quite demanding in that, watercolour techniques are unique to watercolour. Unlike oil and acrylic painting, where the paints essentially stay where they are put and dry more or less in the form they are applied, water is an active and complex partner in the watercolour painting process, changing both the absorbency and appearance of the paint as it dries. The difficulty in watercolour painting is almost entirely in learning how to anticipate and leverage the behaviour of water, rather than attempting to control or dominate it.
Watercolour paint is traditionally and still commonly applied with brushes, but modern painters have experimented with many other implements such as sprayers, sponges etc, combining watercolour with pencils, charcoal, acrylic paint and so on.
Myself at present use the traditional method of applying watercolour paint to paper by the brush method to establish my own unique style.
The method used to reproduce prints from my original artwork pieces is called Giclée (click here for details).