..."A common malady among artists is we sometimes don't know when to quit. Consequently we can ruin a good painting by overworking it or by leaving it too soon. There's a fine line there somewhere and it's hard to know when you've crossed it." Lesley White

How do you know when a painting is finished?  It is one of the most frequent questions I am asked, by artists, and sometimes by people who just appreciate and enjoy art and are curious to know how an artist decides when they have completed the painting.   Is there a formula or process that enables you to know when it is time to put down the brush? I don't think so.  

There is no simple, one size fits all, response or solution either, and no one can tell you when the painting is done, it's between you and the painting to sort that out.  Obviously the better and more experienced painters have a better time of it.  This is why in the studios of the Masters of old those final touches would be left to the Master alone.  Still, paintings don't always turn out the way you might want, or expect them to.  It is an issue that even many great artists struggle with as well; Leonardo Da Vinci and Rembrandt come to mind.

I realized some time ago that I am one of the fortunate artists that has very little trouble knowing when to sign off, pun intended, on a composition.  Plus, I rarely have paintings that don't turn out the way I want and end up in the fire pit.  I think it is partly because of my personality, and also my painting style. 

That said, here are a couple of waterfalls paintings I did that seemed like they were finished but I later made some changes to them that I was happy with.  No structural changes to the compositions, just light and color.  The 'finished paintings are on the right:

This one had a more than a few finishing touches added to it, I made some major changes after I realized that the painting was not matching the vision I had for it at the start.

This one had a few maybe not so insignificant tweaks and adjustments to the light and colors. 

There are some tips that experienced painters often use to help them get to the finish line: Standing back and squinting; showing the painting to an impartial critic; looking at it backwards in a mirror; leaving it aside for a time,... It's a good idea to try out some of these ideas if you get stuck.  

Here are a few choice quotes from artists on the topic;  some are philosophical, some more practical, and some are just funny.

"...a piece is finished when the master has achieved his intention in it"  Rembrandt

"A painting is complete when it has the shadows of a god."  Rembrandt

"Every great painting is left incomplete at the point where its completion is obvious"  Robert Brault

"The painting is always finished before the artist thinks it is"  Harley Brown

"One always has to spoil a picture a little bit in order to finish it."  Eugene Delacroix

"The best way to finish a painting is to start a new one."  Silvio Gagnon

"That's the terrible thing: the more one works on a picture, the more impossible it becomes to finish it."  Alberto Giancometti

"...letting well enough alone – which is the rule for grown artists only." Winslow Homer

"Great is the art of beginning, but greater is the art of ending." Hennry Wadsworth Longfellow

"While adding the finishing touches to a painting might appear insignificant, it is much harder to do than one might suppose..." Claude Monet

"I'm never finished with my paintings; the further I get, the more I seek the impossible and the more powerless I feel." Claude Monet

"The strength and clarity of the picture you envision at the start will tell you when you are done. You are finished when you have said what you wish to say, when nothing added can make it better." Richard Schmid

"The minute you finish a piece, get rid of it! If it's bad, it'll drag you down, if it's great, you'll just sit there looking at it."  Unknown

"When a thing is not worth overdoing, leave it alone!"  Henry S Haskins

"I'm finished when I can't stand it anymore." Ron Mosma