C5 Red Gusset String & Washer Envelopes (Qty 100) 229mm x 162mm x 25mm1 2 day delivery as standard on this product These red string & washer envelopes are C5 size 229mm x 162mm, so fits A5 size paper or half folded A4. The 25mm gusset means they fit bulkier mailings and packs brochures. Made from high quality 160gsm paper. The string and washer fasten is not only quite cool and retro, it also means you can re use re seal the envelope, making them good for the planet too! The string & washer envelope makes a unique