For those of us born in the middle of the last century it is customary, when invited out to dinner to take along a small gift to thank one's hosts.
Kerneels & Kie makes envelopes with either a straight-edged flap for those who don't like frills or a Victorian flap for those who do like flowing lines.
We make them of any paper of suitable weight so they make an impact as part of an advertising campaign and they will certainly be noticed at a conference or if used for invitations to a wedding.
They also spread a little joy in ordinary interactions, handing over the money for raffle tickets sold (I think a straight-edged flap would be appropriate here) or returning a bangle left on the bathroom shelf after a stay.
Speak to us about your requirements, let us work with you to give you what you require.