Do you have a favourite recipe?
When you make that favourite recipe do you substitute ingredients and expect it to turn out the same yummy dish that it always does?
Think apple crumble... I go to the pantry to get the ingredients... whoops , no apples , but I do have lots of carrots, wonder if that'll work. And the oats jar is empty, but maybe I could use rice flakes- they look the same. Raw sugar? Hmm, now where did it all go- polenta looks a bit like it , I wonder if my husband will notice? Sugar is bad for him anyway.
What can I use instead of cinnamon - curry powder?
Are you sensing a theme here? When you follow a recipe you need to stick to the correct ingredients (or very close) to get consistent (and edible!) results.
The same thing happens when you're painting. You need to know exactly how each element will react with the others in your work. If you make wrong choices, particularity with watercolour, you can quickly end up with a muddy mess. If you choose carefully, your materials will mix readily to make the colours and effects that you want. This can save you time and frustration , just like making your apple crumble.
It's also important to use good quality materials for both cooking and painting, or you'll be disappointed with your results - choose wisely and you're much more likely to succeed.
Recently in a workshop I watched someone struggling with student grade materials (which they had chosen to use). While they were competent painters , they were very disappointed with the results . Enough said.
Enjoy your dinner....