They are one of a dozen town retailers supporting the festival with Newton themes.
and their Westgate window featured astronaut Tim Peake and Newton himself, old metalworking instruments and a perpetual motion model.
Runner up was the Teaspoon Tea Company, winners in 2014, who used rockets fuelled with gravi-tea.
Judges also liked K & Co on Westgate, who displayed Newton facts suspended from a tree.
"You could easily spend 20 minutes just reading those," said judge Frances Cartwright, SKDC Executive Member, who was looking for impact, effort and message. "It's great to see our traders getting in the festival spirit and I would urge everyone to go and see what they have come up with."
All retailers have received tickets to the festival.
Entrants were Community Books, Belvoir Gallery, Glen Esk Flowers, Kays of Grantham, Cafe Leo, Pretty Posh Walls, Tee One Golf, Aurora and Grantham Computer Centre