Tri-fold brochures are one of the most common brochures. They are thin and convenient to carry and tempt viewers to open it as they cause intrigue.
These brochures are economical to print since they are basically standard-sized prints (usually LTR or LGL) on light stocks that are folded in three. They have 6 panels to place information on, which is an advantage over other types of brochures.
However, this is not always true: the tri-fold morphology adapts to larger brochures. In these cases, they usually have triple or double-LTR pages, and the stock used is of higher quality.
Viewers are tempted to open these kind of brochures, as they cause intrigue. So, they are suitable for designs of good impact.
They are intended to be handed over to people: ideal to put in folders, or as a more elegant alternative to the flyer in trade shows.