Gouache has become very popular with oil painters and watercolorist because one can use them like watercolor but also use it thicker like oils or acrylics. There is watercolor gouache and acrylic gouache but what they have in common is that they are both opaque paints that give you a matt finish, meaning that they cover really well and you can not see through this
paint like you can with transparent watercolors.
In the past most companies used white chalk additive filler into their gouache to make it opaque. Many companies still do that to this day. Holbein gouache paints however does not use whitening filler but grinds the paint finer and has a filler that they only use in their company . Compared to watercolors, gouache has larger amounts of finely ground pigments, and its particles are packed more tightly
together. more, tightly packed particles leave less space for light to slip through, and that’s what makes gouache opaque. Some manufacturers include a white chalk additive to further reduce transparency, this is something Holbein does not do so this giving you a brighter and more intense colors that are not chalky looking like they were made in the past. Both watercolor and watercolor gouache are suspended in gum arabic.
a good way to see for yourself
the differences and similarities this pigments has is to buy a tube of watercolor and buy a tube of the same color gouache and then play with both to see for yourself the difference you can get with them along with some of the similarities you can get with both.
