Creating space above the bouquet


Why is there a wooden strip on the canvas that Van Gogh used to paint his Sunflowers

That’s what the conservator wanted to find out when she examined the painting in the Van Gogh Museum. The strip increases the size of the canvas, so was the change in the composition a decision of the artist himself?

An X-ray of the painting shows that the cross-hatched brushstrokes that Van Gogh used to paint the background of his still life continue onto the strip. Chemical analysis of the paint confirmed that the paint used on the strip was exactly the same as on the canvas. In other words, Van Gogh added the strip himself. But why?

When Sunflowers is removed from its frame, you can see that a wooden strip has been fixed to the canvas.

Photo of the back (upper part) of Sunflowers.

Photo of Sunflowers from the side, showing the added wooden strip.

Sunflowers without its frame during the research.

More space...

Van Gogh probably realized while painting the still life that the flowers at the top were too close to the edge. To allow more ‘breathing space’ above the bouquet, he added a wooden strip. He then carried on painting. 

To disguise the join between the canvas and the wood, Van Gogh painted a few long, green petals over it.

X-ray of Sunflowers

In 1961, a conservator reinforced the join between the strip and the canvas using glue, nails and bolts. The new, metal bolts are clearly visible in the X-ray. You can also see the old nails, probably the original ones used by Van Gogh.

X-ray images let you see below the surface of a painting. Dense materials such as pigments which contain heavy metals, absorb more radiation than ones that are less dense. These differences are visible in the X-ray. Metal objects such as nails or brushstrokes that are thicker or contain heavy metals appear lighter or even totally white.


The conservator found fingerprints in the paint at the top of the painting. Van Gogh must have gripped the still life here before the paint had dried completely.

Detail of the upper part of Sunflowers, with fingerprints.