Mediums help you to alter and enhance the characteristics of your water colour. By adding the appropriate medium, you can further expand your options by increasing granulation or texture, improve blending and lifting, create iridescence, reduce drying time, and so on.
Mediums extend the artistic possibilities of your water colour without any risk to the permanence of the paintings.
The paper you choose for water colour and gouache will have a significant influence on your final painting. The paper's characteristic behaviour, determined by its manufacture, and the colour, weight and surface texture of the paper will have a profound effect on the character of your work. It is therefore essential to understand the nature of each paper you use and to choose carefully.
You can, of course, paint on any paper that suits your purposes, but there are papers made specifically for painting with water colour and gouache. Both mediums use the same surfaces as they are both based upon Gum Arabic and are used in exactly the same way.
Generally there are two qualities of paper available, both are mould made for greater stability. The first is made from cotton (or "100% rag") and the second from chemically processed wood fibre (known as "woodfree" paper).
For fine art work, water colour papers are recommended if the artist wants to be able to exploit the widest variety of techniques and ensure long term stability.
Sable brushes are the best brushes for water colour use due to their excellent colour carrying capacity, ability to point, and to spring back into shape. Winsor & Newton Series 7™ Kolinsky sables are the world’s finest, first made for Queen Victoria in 1866. Their unsurpassed excellence can in part be attributed to the rigorous selection of only the highest quality raw materials.
There are also a number of excellent sable/synthetic blends and synthetic brushes available, however, such as Sceptre Gold™ II and Cotman™ which offer lower priced yet high performance alternatives to