Personal letters should be handwritten on white, ivory or cream paper, with a minimum weight of 100 gsm to avoid show through. The standard size is either W6¼ x H8 inches (16 x 20 cm) or W5½ x H7 inches (14 x 18 cm).
More contemporary styles may be in more adventurous colours, with matching or contrasting envelopes.
Watermarked paper is usually a sign of good quality.
Use a lined undersheet to keep text straight, and use black or blue ink.
A personal letterhead should include postal address and telephone number.
Do not include your name or email address in a letterhead used for purely social personal correspondence.
If budget allows, have letterheads engraved.