Next to it are a number of small brushes and what looks like a cocktail stick and a box full of cotton wool.
Taking a knife to a multi-million pound painting by the world's greatest horse painter might seem like madness.
But for Viola Pemberton-Pigott these are the tools of her trade.
For more than a year she and colleague Anna Sandén and their small team of assistants (Sam Hodge, Tabitha Teuma, and Simon Bobak) have toiled day and night on Scrub, painted in 1762 by Liverpudlian George Stubbs.
On Friday, September 12, the results of their painstaking work will go on public display when the lifesized portrait is unveiled in Leeds City Art Gallery after a £100,000 restoration paid for by property mogul Kevin Linfoot.
It will hang next to its sister painting Whistlejacket in The White Gallery as part of the Large as Life exhibition of Stubbs' horse paintings.
Viola said: "A great artist is a pleasure to work with. And Stubbs does paint animals like nobody else. A second-rate artist does't give nearly as much pleasure.
"Having said that this has almost been tyranny due to the extent of the damage.
"Anna and I have been working on it every day for as long as I can remember. I don't think Anna's family know who she is!
"I will be so relieved when it goes back up North."

History

The damage she refers to reflects the oil painting's chequered history.
It was rejected by the man who commissioned it, the second Marquess of Rockingham, for an unknown reason.
Then Scrub was literally folded up and transported to India only to be sent back unfit for sale. Art historians believe Stubbs took it back, possibly restoring some of the damage caused by the voyage.
After his death in 1806 it disappeared off the radar and only resurfaced when it was bought by the fifth Earl of Rosebery in 1898.
Scrub then passed by descent to its current owner, Lord Halifax.
When it arrived at Viola's London studio in March last year large sections of the canvas were yellowed as a result of at least three previous restorations, the last in the 1950s. Donning their magnifying goggles Viola and Anna embarked on a deep clean which took almost a year to complete.
Viola said: "Whistlejacket has had very few movements in its lifetime and so has stayed in almost pristine condition.
"But because Scrub was so overpainted we had no idea as to the extent of the damage we eventually found underneath.
"When we were cleaning it we were also very mindful that we might be removing a Stubbs' repaint.

Texture

"We found many different sorts of filling on top of each other.
"The paint we were taking off was changing in tone and texture so we had to take it millimetre by millimetre."
Minute cross-sections had to be taken regularly and placed under a microscope to assess which layers of paint were original. After 10 months of intensive work using cotton wool swabs dipped in solvents as well as the scalpel, the painting was relined by Simon Bobak to reinforced the original canvas by gluing it to a new one.
The cleaning was completed in April and since then Viola and her team have been repainting areas of Scrub where the original paintwork has worn thin or even disappeared.
Viola said: "If you don't get the layers one after another repeating each other you don't get the luminosity of the paint which is so crucial to Stubbs's achievement as a painter.
"The exciting thing was as we began to get through the repaints you could see the original Stubbs underneath .
"The whole thing began to take shape as lot of the subtleness had been covered up. Even the clouds in the background are fantastically detailed."
Their work, which goes on well into the night thanks to the 'day' lights suspended above their raised seating platform, will continue right up to next week's unveiling.
And thanks to her and her team's efforts on September 12 the public will finally get to marvel at what is no longer a hidden masterpiece.