Postal stationaries, such as envelopes and postcards, are an important part of philatelic collection because they offer a unique opportunity to collect pre-printed stamps. These items often feature interesting designs and can provide insight into the history and culture of a particular place and time. Postal stationaries, including inland letters, are also a useful tool for collectors who are interested in studying the postal rates and policies of different countries, as they often bear the official postage rates for various types of mail. Envelopes, postcards, and other postal stationaries can add depth and variety to a stamp collection and offer insights into the history of postal systems and communication.