Letter Sheet and Informals Etiquette

Letter Sheet
Size: 51/4 by 71/4 inches high.
The letter sheet is a formal stationery style. It can be used for extending and replying to informal invitations or for replying to formal invitations. (You may not want to use a letter sheet that is engraved informally with the address only to extend an invitation.) This stationery should be of white or off-white stock. The sheet comes folded vertically with the crease on the left. You can engrave it with a crest, monogram, name only, or address only—although it doesn’t have to be engraved at all.

Informals
Size: 5 by 31/2 inches wide.
In spite of its name, the informal is a pretty formal piece of stationery. Men use informals only when they are engraved with a couple’s name on the front. Informals can also be engraved with a woman’s full name. They are appropriate for writing notes, gift enclosures, extending and replying to informal invitations, and replying to formal invitations.