From 1973, GRATALOUP will use a new pictorial technique, that of free canvases (without frame), resulting from his research with his friends painters of the movement Supports Surfaces.

He will also experiment free canvases, stretched on frames
metal by nylon threads, leaving an empty space between the canvas
and the chassis.

In 1973, he took over the rubbing of the Irish Sea series (1970) and made his first free and/or stretched canvases.

The canvases stretched on metal frames are present, even today, throughout the work of the painter; the free canvases were made in this period only.