Collection: Square Envelopes

Square envelopes are available in over 220 sizes from compact 40 x 40mm through to 220 x 220mm and beyond — the contemporary format of choice for wedding invitations, premium greeting cards, social media-ready mailings and any application where a distinctive, symmetrical presentation matters. Available in 30–350gsm paper weights across a range of colour options.

The most popular square sizes are 155 x 155mm (fits a standard square invitation card), 160 x 160mm and 130 x 130mm. Square envelopes can be used for greeting cards where the square format gives a more contemporary, considered look than a standard rectangular envelope.

Benefits of Square Envelopes

• over 220 sizes — from small enclosures through to large 220 x 220mm formats.
• Contemporary format — the preferred choice for modern wedding invitations, premium greeting cards and standout direct mail.
• Paper weights 30–350gsm — including premium options for heavyweight invitation card.
• a range of colour options — full colour range available for occasion-matched or brand-matched presentation.
• Gummed and peel & seal — closure options for both personal and volume use.

Frequently Asked Questions

Are square envelopes more expensive to post than standard envelopes?
Square envelopes in small sizes (under 240 x 165mm) post at the standard large letter rate — there is no automatic Royal Mail surcharge for square envelopes. However, square envelopes may need to be hand-sorted by Royal Mail if they fall outside their automated sorting machine dimensions. Always check current Royal Mail guidelines and confirm your specific size qualifies for the intended postage rate before posting at volume.

What size square envelope do I need for a wedding invitation?
The most common wedding invitation square card size is 148 x 148mm, which fits a 155 x 155mm or 160 x 160mm square envelope with clearance. For a 130 x 130mm card, use a 140 x 140mm or 155 x 155mm envelope. For cards with inserts (details card, RSVP), allow extra space — the combined thickness of multiple cards in a square envelope may require a slightly larger envelope than the card size alone suggests.

What paper weight should square envelopes be for wedding invitations?
A minimum of 100gsm is recommended — lighter paper feels insubstantial and does not complement quality invitation card stock. 120gsm gives a premium result. The range covers 30–350gsm. For foiled or embossed invitation cards where envelope opacity matters, choose a higher gsm option or check the opacity specification on the product listing.

Can square envelopes be printed on?
Yes — smooth and wove finish square envelopes accept inkjet and laser address printing on most standard printers. Heavily textured, pearlescent or metallic finishes may not feed cleanly or accept ink reliably — test a small batch before printing the full run.