The Mark 1 set introduced in 1959 underwent numerous modifications, each of which merited an advance in Mark Number. None did, the Army saving up “Mark 2” for a completely new set of Patt. ’58, which reproduced the final issues of all component parts, but was made in a smooth-coated nylon. Its components achieved COSA listings as “Troop Trials Item”, but it never went into service. Long into the Atomic Age, the Army was forced to a recognition that cotton webbing had a problem – it could not be easily decontaminated under NBC conditions. Mark 2 Patt. ’58 was one solution that was investigated, along with Patt. ’75 P.L.C.E. in the same material and two alternative patterns, “A” and “B”, of what most collectors call “SA 80 webbing”. These were in a new material, akin to “brushed nylon” in texture and, after yet more development, a design emerged as Patt. ’90 P.L.C.E.