I use a retouching varnish ...

I use a retouching varnish which is made in France, Libert, and that's all the varnish I use.
 Edward Hopper

Quotes from the same author

One of the weaknesses of much abstract painting is the attempt to substitute the inventions of the intellect for a pristine imaginative conception. The inner life of a human being is a vast and varied realm and does not concern itself alone with stimulating arrangements of color, form and design. The term 'life' as used in art is something not to be held in contempt, for it applies all of its existence, and the province of art is to react to it and not to shun it. Painting will have to deal more fully and less obliquely with life and nature's phenomena before it can again be great.
 Edward Hopper
There will be, I think, an attempt to grasp again the surprise and accidents of nature and a more intimate and sympathetic study of its moods, together with a renewed wonder and humility on the part of such as are still capable of these basic reactions.
 Edward Hopper
If the technical innovations of the Impressionists led merely to a more accurate representation of nature, it was perhaps of not much value in enlarging their powers of expression.
 Edward Hopper
The trend in some of the contemporary movements in art, but by no means all, seems to deny this ideal and to me appears to lead to a purely decorative conception of painting.
 Edward Hopper