Cannot remove grid for hv.QuadMesh

t=np.arange(0,10, 1)
f=[0.1*2**n for n in np.arange(0,10,1)]
mt,mf=np.meshgrid(t, f)
hv.QuadMesh((t,f,0*mt)).opts(show_grid=False, cmap='gray', width=400)

show_grid has no effect, neither does the option grid_style.
Any workaround?

Not so much the grid, but the edges of the cells. I remember there being an option in heatmap, but I can’t find it