I claim the ornamental design for a roll-up pen holder, as shown and described.
FIG. 1 is a perspective view of a roll-up pen holder, showing my new design in a flat configuration;
FIG. 2 is a bottom plan view of FIG. 1;
FIG. 3 is a top plan view of FIG. 1;
FIG. 4 is a rear elevational view of FIG. 1;
FIG. 5 is a front elevational view of FIG. 1;
FIG. 6 is a top plan view of FIG. 1;
FIG. 7 is a bottom plan view of FIG. 1; and,
FIG. 8 is a perspective view thereof, illustrated in a rolled configuration.
The broken lines showing pens in FIGS. 1 and 8 depict environmental matter and form no part of the claimed design. The broken lines on the design depict stitching and form part of the claimed design.