I use twoway area to draw chronograms, and like to suppress the outline of the area, using fill-colour only. However, in interactive mode, Stata puts a black outline around the last category. This does not happen when exported to PDF or EPS, but it is reproduced in export to PNG:

Array

The desired output is as follows (achieved via export to PDF):

Array

The graphics command is as follows (full example below):

Code:
twoway area xx* t, lwidth(none none none none)
The lwidth() option suppresses the outline of each colour area.

MWE:

Code:
set obs 1000
gen x = runiformint(1,4)
gen t = 1 + int((_n-1)/10)
tab x, gen(xx)
collapse (sum) xx*, by(t)

replace xx3 = xx3 + xx4
replace xx2 = xx2 + xx3
replace xx1 = xx1 + xx2

twoway area xx* t, lwidth(none none none none)