I have been given to understand that this subject has been discussed many times by Pablo Picasso. The essence of what he had to say is as follows.
If when putting down the initial layers of your painting you find one small passage that appears absolutely fabulous you might decide to leave this section alone and continue on with the rest of the painting not daring to touch this magical section again because there would be no way you could achieve that effect again. The advise from Picasso would have been– you must destroy that section straight away, that is arty not art. Art is something that the mind and hand can achieve and that you have the ability to achieve again if need be. So if you like to keep those accidental effects just ponder on what is written here. I cannot supply evidence that Pablo Picasso said this. This is the story as told to me by the late Nick Heiderick.
After a bad days painting this is what was left on my pallet. An example of Arty but not Art. Howard Sparks