Recently a customer asked me to do some teatowels in yellow. I've never done much printing with this colour before - the closest I've got is a burnt orange.
So lots of experimenting and large quantities of ink were used last week to try to produce some "nice" yellows. It is definitely the hardest colour I have had to print with - very difficult to predict the final outcome on my unbleached and oatmeal teatowels - and even on cream. So there were lots of test colours on strips of cloth and by the time I had found something I liked I had forgotten the proportions - of course I had not methodically written them down.
After a few disasters I found that mustard is yellow with a touch of brown (from a Google search of course) so that was one success eventually. But is mustard yellow? Too much yellow with white and brown turns the ink a vivid garish orange. Some might like this I suppose but I prefer more subtle colours. Even using yellow straight from the Permaset pot on cream linen is too bright for me. Another hurdle - if the mixed colour is too light and transparent, the print disappears on unbleached linen. I finally discovered using white (a mixture of standard white and supercover white) and yellow produces an attractive lemon colour.
So it's off to the library to find more information on colour theory and colour mixing, and a closer look at the colour wheel tool!