The ornamental design for a papertowelholder, as shown and described.
FIG. 1 shows a perspective view of a paper towel holder showing my new design; the broken-line disclosure of the paper towel roll being for illustrative purposes only and forming no part of the claimed design.
FIG. 2 shows an overhead view of the paper towel holder.
FIG. 3 shows an underside view of the paper towel holder.
FIG. 4 shows a first end view of the paper towel holder.
FIG. 5 shows a second end view of the paper towel holder.
FIG. 6 shows a rear view of the paper towel holder; and,
FIG. 7 shows a frontal view of the paper towel holder.