A printable sheet material includes a panel having an integral separable portion and a starting mechanism formed on the separable portion. At least two tearable lines are formed in the panel permitting the separable portion to be at least partially separated from a remaining portion of the panel by tearing in either of opposite directions. Each tearable line includes a plurality of open “V” channeling cuts spaced along the line, each of the channeling cuts formed by a pair of converging cuts having a wider spaced end and a narrower spaced end. The channeling cuts are oriented with the wider spaced ends facing toward the starting mechanism and the narrower spaced ends pointed in a tearing direction extending away from the starting mechanism. The channeling cuts of the two lines share one of the converging cuts.