A strong and practical mailing solution for sending larger documents, plans, artwork, reports and bulky flat items through the post. These C3 gusset envelopes are designed with an expanding side gusset, giving you extra room when a standard envelope just won’t do the job. Expands up to 30mm, making it ideal for thicker paperwork, large documents, plans, binders and bulkier contents. C3 size is suitable for A3 sheets and larger flat documents, helping keep contents neat and professional. Perfect for paper, reports, plans, artwork, folders, catalogues, binders and office documents. These C3 gusset envelopes are made for mailing larger items that need more space than a standard envelope can offer. The 30mm expanding gusset gives extra capacity, while the 140gsm brown manilla material prov.