One of The Spider's distinguishing features is his "calling card." Wentworth often leaves a red-ink "spider" image (like a drop of blood) on the foreheads of the criminals he kills, so others will not be blamed. In the sixth novel (1934), the Spider imprints his red sign on a gold ring so that any who need his help can use it by taking it to Kirkpatrick (where Wentworth will find out about it). During the same time period, in the same benign fashion, and perhaps inspired by The Spider's calling card, Lee Falk's long-running 1936 syndicated comic strip hero, The Phantom, left a distinct skull mark in the faces of those enemies he fought, made by the ring he wore. The Spider's seal, however, was concealed in the base of his platinum cigarette lighter and was invented by Professor Brownlee. The Spider also carried a thin silken line (his "web") which had a tensile strength of several hundred pounds.