6 1/2 x 6 1/2, 165 x 165mm, Square 68lb Text, 101g/m2, Matte Euro Flap, Envelopes Storm Cloud, Blue, Gmund Colors Matt 25 Pack 6 1/2 square invitation envelopes in our contemporary Euro-Flap (deep neck) style are made from Matt Color (44) Storm Cloud 68lb text weight paper. The deep pointed euro flap design is the first choice for formal invitations that require an envelope with style and distinction.