Since the dawn of the Hollywood age over 100 years ago, movie posters have been used as a medium to promote films with a commercial intent of getting people to buy tickets. Over the years the style of movies has evolved and with it, the design of movie posters has also changed.
Below you can see a description of many common poster types and other items (such as lobby cards and stills). We don't list everything that exists because that would be thousands of different types! But this is a great beginners guide to many movie poster sizes the U.S.
24-sheet: are 9 feet by 20 feet and were originally (in the 1920s) printed in 24 one-sheet sized (27" x 41") pieces. Over the years, as printers were able to print on larger sized sheets, the number of sheets needed for a 24-sheet gradually diminished until the point where most were printed on 12 unequal-sized pieces.
Six-sheet: are 81" x 81". When the studios began making posters, they could only print sizes up to 27" x 41". So, in order to make the 81" x 81" poster they printed six sections of the smaller size that could be combined to form the larger poster (this is why they are called "six-sheets").
Three-sheet: are 41" x 81". When the studios began making posters, they could only print sizes up to 27" x 41". So, in order to make the 41" x 81" poster they printed three sections of the smaller size that could be combined to form the larger poster (this is why they are called "three-sheets").
One-sheet: are 27" x 41" and are the standard movie poster size... what you see outside of any movie theater and use from 1896 until roughly 1990 (since then, most one-sheets measure 27" x 40").
Half-sheets: are 22" x 28" and are printed on heavy card stock, the same as inserts, and similar to that of lobby cards. They were sometimes folded twice immediately after printing, although sometimes they were left unfolded, but most collectors don't consider folding in this way a defect. Most movies have two different styles of half-sheets. The "A" style (sometimes these have a "T/A" in the corner of the poster) which is almost always the exact same image as the title lobby card. The "B" style is almost always an image that appears on no other size of movie poster for that movie! Note that these were almost always referred to as "22x28 displays" in pressbooks, and NEVER as "half-sheets".
Lobby Cards: are 11" x 14" and were almost always printed in sets of 8 (some lower budget movies only had a set of 4). Many lobby card sets (usually pre-1970 sets) have a "title card". A title card normally has artwork and the credits from the movie and is different in appearance from the other seven cards in the set.
Window cards: are 14" x 22" and were printed on heavy card stock (thicker than lobby cards, half-sheets, or inserts). Almost all window cards were printed with a blank space (usually 4") above the poster image, where a local theater could print in their name and play dates (sometimes they would glue on snipes, handwrite the information, or leave the top blank).
Window cards JUMBO: are 22" x 28" and were printed on heavy card stock, the same as regular window cards (thicker than lobby cards, half-sheets, or inserts). They are basically the same as the regular window cards, except much larger and consequently much more striking!
Window cards MINI: are 8" x 14" and were printed on heavy card stock and originally known as "midget window cards".
Mini window cards are certainly far more scarce than title cards or regular window cards, and probably about equally as scarce as jumbo window cards.
Inserts: are 14" x 36", and are printed on heavy card stock, the same as half-sheets, and similar to that of lobby cards. They were sometimes folded twice horizontally immediately after printing, resulting in three horizontal folds, although sometimes they were left unfolded, but most collectors don't consider folding in this way a defect
U.S. Heralds: are different sizes and were made from the 1910s to the 1980s or so. Theaters would order heralds by the thousands (they usually cost around $3 per thousand!). They would then hire people to stand on busy street corners and pass them out to all who walked by. Most heralds are a single sheet of paper that is folded in half, creating four small pages. The front of the herald usually has just the title of the movie and images of the stars (like a small poster) and the two middle pages usually have a lot of information about the movie along with more images (and sometimes these images are found nowhere but the herald). The back page is usually blank for the theater to print in their name and play dates, to let people know where the movie was playing and when. Sometimes one or more of the pages were full-color, and often some of the pages were two-color.
Pressbooks: are different sizes and were special advertising booklets sent directly to theater owners that were playing the specific movie advertised in a particular pressbook (almost all pressbooks were for one movie only, although there were some double-bill pressbooks). A pressbook was made for every movie, starting in the mid 1910s through the 1970s (somewhere in the late 1960s, studios introduced "press kits", which included brochures and stills from the movie, but NO images of the posters, and for a few years, they made both, but then they stopped making pressbooks and only made press kits). There is no "standard" measurement for them, though each studio usually issued them at the same measurement during different periods of time.
Pressbooks were sent to movie theater owners to help them promote the film. They have lots of "newspaper" black and white ads in various sizes for theaters to use in their local newspaper (theater owners would literally cut out the ad they wanted to use and give it to their local paper, which is precisely why so many pressbooks have ads cut out of them). For collectors, the most important thing about pressbooks is that they show many of the posters that were created for the film (one-sheet, three-sheet, etc.).
Sometimes not a single copy of a poster is known to exist and the only way you can tell what the poster looked like is by looking at a picture of it in the pressbook.
Glass slides: are 3 1/4" x 4" and made from the early 1910s through the early 1950s. They were shown in between movie showings, while the audience was entering the theater. They would be projected onto the screen, and they would either be an advertisement for an upcoming movie, or an ad for a local business. They are often quite scarce, especially in good condition (as they often broke; being made of actual glass, they are fragile).
Sometimes they had images that also appeared on the title card or the posters, sometimes the images came from newspaper ads, and sometimes there were images that do not seem to have appeared anywhere else! There were two types of glass slides, one with a single piece of glass stapled into a cardboard holder, and the other with two pieces of glass that were held together with black tape.
Stills: are 8" x 10"photographs usually printed on thin glossy photo paper that were created for all movies from the 1910s through the present day. Studios would often issue dozens of different stills for each movie (usually well over 100!), and they would be sent to theaters showing the movies. Starting in the 1960s, many dealers began reproducing stills (sometimes from the original negatives), and sometimes it can be difficult to distinguish between original theater-used stills and reproductions (the main differences are the quality of the paper and the crispness of the photographic image and the sharpness of the letters or numbers).