[NTG-context] Text to edges of page

Hi all, I would have though the following code would produce text flush to the edges of the "paper", but there is significant whitespace on the right and bottom sides. Probably there is an obvious setting, but it eludes me now: \definepapersize[short][width=600px,height=440px] \setuppapersize[short][short] \setuplayout[ backspace=0mm, topspace=0mm, margin=0mm, header=0mm, footer=0mm ] \setupindenting[none] \setupwhitespace[medium] \setupinterlinespace[22pt] \starttext \input Tufte \input Knuth \input Tufte \stoptext