It is possible to print onto watercolor paper, but I can only relate
my experience with the Epson Stylus Color 760.
Use a 140grm paper and make sure this is the only paper in the
printer,
and use a single sheet at a time, and obviously A4 or smaller.
Most printers have an adjustment lever to cope with thicker paper,
so make sure this is set for the thicker variety.
After pressing 'print' on the computer you may have to gently push the
paper down into the printer until the mechanism 'grabs' it to feed it
through.
Best of luck........dart36.