in my experience: frosted contact paper is probably not conveniently
available in large sizes so a seam or overlap will be needed. the spray
frost stuff will certainly come out uneven. a reflective tint will be
as see-thru after sunset as a sheer curtain. why not take a snapshot
and some measurements and outfit it with a privacy curtain of a
two-sided flannel or other privacy material print you pick out for fun
or to match the other windows. if you're strapped for a skilled
seamstress check your local dry cleaners or continue to hang out in the
sewing/crafts department at walmart where you find the fabric you want.
you may want to look out the door to see who's there so consider a
double upper curtain rod above with a single rod below holding the
outside sheer and the inside privacy on a spring rod. cheapest would be
a large solid hemmed pillowcase or wide hemmed flat bed sheet. cut hem
at edges to give you curtain rod access. vinyl shower curtains are
another possibility unless direct sunlight is involved where they will
deteriorate more quickly. consider a wide angle peephole if you are
permanently blocking the window by screwing up decorative double sided
framed art.