scrim 14 having crenulations 38 and 40 that are irregular in spacing as well as irregular in shape there is no symmetry between crenulation 38 and 40 and seemingly no pattern of repetition fig6 depicts a scrim 14 having crenulations 42 and 44 similar to fig3 however the crenulations of fig6 extend in both directions relative to imaginary lines ab and dc in a similar fashion crenulations 46 and 48 of fig7 illustrate a repeating shape of irregular spacing of crenulations entirely on one side of imaginary line ab and extending outside of imaginary line ab while crenulations 48 extend in both directions of an imaginary line cd in fig8 a scrim 14 is illustrated as being used over a pin seam 20 or other type of join that has approximately a 15 to 45 open area and may be approximately 4 inches wide having a thickness of between 0 003 inches to 0 010 inches thick the scrim is made of a high strength and wear resistant material such as a high density polyethylene polyester or polyurethane a low melt adhesive layer like ethylene vinyl acetate eva may be coated on the scrim to improve fiber bonding of scrim 14 to fabric 12 crenulations 50 and 52 are a repeated pattern of semi circular shape approximately 0 5 inches deep and spaced approximately 1 inch apart the permeability of the finished fabric assembly.