A 6 × 6 envelope is made to neatly hold square stationery such as:
145 × 145mm inserts
Square greeting cards
Wedding invitations
Save the dates
Thank you cards
Birthday cards
RSVP details cards
Handmade card designs
Small square photo prints
Keepsake notes
Craft and luxury stationery
Using a 6 × 6 envelope gives your square cards enough space to slide in smoothly without looking loose or oversized. It helps keep your stationery protected, tidy and professionally presented, whether it’s for weddings, gifting, handmade cards or everyday occasions.