The studio was "his world". There one did not notice much of "lovers waiting in the dunes until white smoke came from the annex". There one discussed all kinds of painting techniques and especially maturing. The paint, oil paint had to mature.

During an exhibition by members of the Arti Society in Amsterdam, colleagues were delighted about a still life with pears, which was beautifully matured.

Thijs could talk about this so vividly that I, as a drawer became jealous of painters. As a painter Thijs wanted to paint the light. The light, as it "hits" across groups of trees and reed borders.

But light often changed during the day and played tricks on the painter, on his perception and on his eyes. Thijs never stopped watching the light as it reflected in the water, whether it was in the southern European ports, the river "Gein" near Abcoude or the straight polder ditches.
Het Gein 1967 gouache 35 x 25

"Put for instance splinters of a broken mirror opposite each other and watch how the sun's reflects, how backlight changes shapes and how shadows are lightened.

In this way he wanted to divide reality in forms, without ending too decorative.