@TruthSandwich @freemo @Pat That's not necessarily the case. It is true that a fountain pen is highly likely to leak as it is to not write or otherwise disappoint.

The ball point pen really became popular and available around the late 50s and early 60s. They shouldn't leak ink but when the ball is depressed when in contact with clothing, the ink will come out continually due to capillary action of the fabric. They do have caps and ways to protect the tip but it only takes one unprotected insertion to ruin a shirt. They are also not distrusted like the fountain pen and this leads to a perfect scenario where it can Exon Valdez a shirt.