or written in calligraphy. Historically, wedding invitations were hand-written unless the length of the guest list made this impractical. When mass-production was necessary, engraving was preferred over the only other widely available then option, which was a relatively poor quality of letterpress printing. Hand-written invitations, in the hosts' own handwriting, are still considered most correct whenever feasible; these invitations follow the same formal third-person form as printed ones for formal weddings and take the form of a personal letter for less formal weddings. Tissues are often provided by manufacturers to place over the printed text. Originally, the purpose of the tissue was to reduce smudging or blotting, especially on invitations poorly printed or hastily mailed before the ink was fully dried, but improved printing techniques mean they are now simply decorative. Those who know that their original purpose has been made irrelevant by dramatic improvements in printing technology usually discard them. Modern invitation design follows fashion trends. Invitations are generally chosen to match the couple's personal preferences, the level of formality of the event, and any color scheme or planned theme. For example, a casual beach wedding may have light, fresh colors and beach-related graphics. A formal church wedding may have more scripty typefaces and lots of ornamentation that matches the formal nature of the event. The design of the invitation is becoming less and less traditional and more reflective of the couple's personality. Some web-based print-on-demand companies now allow couples to design or customize their own wedding invitations. More recently in 2019, foil stamping and foil sleeking invitations have come back into trend. Foil sleeking is applied by applying a thick layer of toner to a paper using all four CMYK colours and a fifth white colour, next the card is fed through a foil heat transfer machine where the foil sticks to the toner and design. The invitation is typically a note card, folded in half, or perhaps French folded (folded twice, into quarters). Other options include a sheet of paper, a tri-fold, or a trendy pocket-fold design. The appropriate paper density depends on the design but typically ranges from heavy paper to very stiff card stock. There are also acrylic invitations. Mailing Traditionally, wedding invitations are mailed in double envelopes. The inner envelope may be lined, is not gummed, and fits into the outer envelope. The outer envelope is gummed for sealing and addressing. More recently, the