Envelope Set, 100 gsm

Details

Twenty-five envelopes to a set, in a 100 GSM wove sheet, with a water-activated gummed flap and no window. An envelope has exactly one job that nobody tests: not showing what is inside it. Hold a cheap envelope with a cheque in it up to a table lamp and the amount and the signature read straight through, and that is a 70 or 80 GSM sheet with an opacity in the low eighties sold as a 100 GSM envelope. The second thing worth naming is the flap. Peel-and-seal is convenient and its release liner is a silicone-coated plastic strip that is thrown away thirty seconds after it is bought, one per letter. A gummed flap is a sheet of paper and a bit of starch.

• Sheet measures 100 GSM to ISO 536, taken from a cut envelope rather than from a reel
• Opacity 93 percent, ISO 2471. A cheque or a payslip inside does not read against a lamp, which is the actual test and the only one that matters
• No window. A windowed envelope carries a film patch that has to be separated before the paper can be recycled, and in practice never is
• Flap is gummed with a water-activated dextrin gum, made from starch. No peel-and-seal, so no silicone release liner going into a bin with every letter
• Seam adhesive is a water-based emulsion, and seam strength is measured rather than assumed. Bursting strength to ISO 2758 on the body sheet
• Diagonal banker seam on DL and A5, pocket seam on A4, which is the construction that survives a thick document without splitting at the corner
• Natural white, no optical brightener added. It is a slightly warmer white than a copier sheet on purpose, because an optical brightener is a fluorescent dye and an envelope does not need one
• Elemental chlorine free, AOX under 0.2 kg per tonne of pulp. ECF is not chlorine free, and we are not going to round that up
• Virgin fibre. No recycled content in this one, because recovered stock at 100 GSM loses the opacity that is the whole point here, and the document wallet in this range is where the recycled board sits
• Sizes are the ISO ones: DL 110 by 220 mm, A5 fits a C5 at 162 by 229 mm, A4 fits a C4 at 229 by 324 mm
• Rs 8.80 an envelope at DL, Rs 11.20 at A5, Rs 14.40 at A4