EB double wall: thickness, flutes per foot and strength

EB double wall pairs an E flute with a B flute, about 0.19 in thick in Packgent's nominal sum. It gives double wall puncture resistance with a print-ready E face, in less thickness than BC.

Key numbers

Construction	Double wall: two mediums, three liners
Plies	E flute + B flute
Nominal caliper	0.1875 in · 4.8 mm
OD minus ID, length and width	0.375 in
OD minus ID, depth	0.563 in
McKee strength vs C flute, same ECT	110%

Caliper is the sum of E flute (0.0625 in) and B flute (0.125 in), computed by Packgent. Real board is slightly thinner after combining and converting.

Strength ratio = √(caliper ÷ C-flute caliper), from the McKee formula with ECT and perimeter held equal.

Trade-offs

Thinner than BC, so lower McKee strength at the same ECT
Smooth E face for printing
Slimmer outside dimensions than BC for the same inside size

Typical uses

Printed shippers for heavier products
Retail-ready cases

Estimated box compression at 10 sizes

Simplified McKee BCT, lbf, empty box, by inside size and ECT
Inside size, in	42 ECT	51 ECT	71 ECT	82 ECT
8 × 6 × 4	565	686	955	1,103
10 × 8 × 6	641	778	1,083	1,251
12 × 12 × 12	740	898	1,250	1,444
14 × 10 × 8	740	898	1,250	1,444
16 × 12 × 10	799	970	1,350	1,560
18 × 12 × 12	827	1,004	1,398	1,614
18 × 18 × 18	906	1,100	1,531	1,769
20 × 16 × 14	906	1,100	1,531	1,769
24 × 18 × 18	978	1,188	1,654	1,910
24 × 24 × 24	1,046	1,270	1,768	2,042

BCT ≈ 5.87 × ECT × √(caliper × perimeter), perimeter = 2(L + W) of the inside size. An estimate; confirm with ASTM D642. Grades shown are ECT values Packgent computes for this wall type, not a list of what mills sell.

Sources

Last reviewed 2026-10-27. See all sources and how Packgent computes.