I have been doing some pen plots with Micron pens using an iDraw pen plotter. I performed some tests to help me select a paper that has great pen quality and performs well for my style of water color. Each pen plot was the same image with the same plotter settings and used a brand new Micron pen on a 22×30″ sheet of paper.
The cold press papers had a rougher texture while the hot press ones were much smoother. My favorite are the Arches Hot Press papers.

Arches Hot Press 140lb

Arches Natural White Watercolor Paper – Hot Press, 22″ x 30″, 140 lb

Arches Hot Press 140lb – Micron 02 – Great Pen Quality.
Arches Hot Press 140lb – Micron 02 – Slight irregularities towards end of plot, but overall great.
Arches Hot Press 140lb – Colors sink in, has nice balance when adding color and retains it. Great.

Arches Hot Press 300lb

Arches Natural White Watercolor Paper – Hot Press, 22″ x 30″, 300 lb

Arches Hot Press 300lb – Great pen quality. Started painting before I got a picture of just the pen.
Arches Hot Press 300lb – Paper is thick, nice and stiff.
Arches Hot Press 300lb – Pretty good, doesn’t allow for a lot of wet mixing.

Arches Cold Press 140lb

Arches Cold Press 140lb
Arches Cold Press 140lb – Poor pen quality. Didn’t even finish the plot or test watercolor.

Artistico Fabriano Cold Press 140lb

Artistico Fabriano cold press 140lb micron 03
Artistico Fabriano Cold Press 140lb – Micron 03 – Earlier in the pen plot, decent line quality.
Artistico Fabriano cold press 140lb micron 03
Artistico Fabriano Cold Press 140lb – Further into plot. The quality of line is poor.
Artistico Fabriano cold press 140lb micron 03
Artistico Fabriano Cold Press 140lb – Watercolor quality is nice.

Artistico Fabriano Hot Press 140lb

Artistico Fabriano Cold Press 140lb
Artistico Fabriano Hot press 140lb – Pen quality is excellent.
Artistico Fabriano hot press 140lb
Artistico Fabriano Hot press 140lb
Artistico Fabriano hot press 140lb
Artistico Fabriano Hot press 140lb – Did not like this one. Maybe good for layering, but did not retain color well.

Canson Heritage Cold Press 140lb

Canson Heritage Cold Press 140lb – Micron 03 – Pen quality is great.
Canson Heritage Cold Press 140lb – Micron 03
Canson Heritage Cold Press 140lb – Dimples cause little color pools; water color sits on top of paper. Not very good.

Canson Heritage Hot Press 140lb

Canson Heritage Hot Press 140lb. Micron 03 – Pen Quality Excellent
Canson Heritage Hot Press 140lb. Micron 03 – Pen Quality Excellent
Canson Heritage Hot Press 140lb – Did not hold color well when applying, like painting on tissue paper on tupperware. Not too good.