Yeah that's it, I shoulda looked first, here it is...

Scrap Yard Knife Co. uses a specialized liquid penetration inspection, which reveals surface breaking flaws by bleedout of fluorescent dye from the flaw.

The technique is based on the ability of a liquid to be drawn into a "clean" surface breaking flaw by what is known as capillary action. (Capillary action is the force that is a resultant of adhesion, cohesion, and surface tension in liquids which are in contact with solids, as in a capillary tube.) After a period of time known as the "dwell", excess surface penetrant is removed and a developer applied. This acts as a "blotter". It draws the penetrant from the flaw to reveal its presence. Ultraviolet "black light" is used in darkened conditions to view the colored penetrants for any cracks, fissures, or other flaws.

What does this mean to you? It means your Scrap Yard knife will be free from microscopic cracks and fissures, invisible to the human eye under normal conditions. Whereas other blades, manufactured by other companies, are sent to customers with "unseen" surface flaws that "crack" under pressure, each Scrap Yard knife is individually inspected to be free from any defects.

So how did that one leak out ?