24 sheets are usually, but not always, made up of four columns - an A,B,C and D column and 3 rows of panels. A1, B2, C3, D1 etc. etc. So, usually there are twelve separate panels which are joined together to make 9x20 foot poster. Of course there are variances over the years. Earlier 24 sheets might have different configurations and sometimes the posters were printed in a different format. But in my experience the aforementioned scheme is the usual case and one that was used for many 24 sheets during the 50s and 60s. But like everything else in movie posters there is the exception that proves the rule. Most 24 sheets that are available for sale as a collectible today were never used. The normal drill for 24 sheet display was to paste the 24 sheet to a billboard panel. When the advertising campaign was over, the advertising company would sell the space to another advertiser and that 24 sheet was simply pasted over the existing one. Periodically all this would be scraped off the billboard panel and the whole process would start over again. One reason why the attrition rate for 24 sheets is as high as it is is that after the very first first run of a film, the economic model to use a 24 sheet for commercial gain was done. After the first run of the picture, there would be little use for a 24 sheet. And so one can conclude without too much doubt that these posters were thrown out by the exchanges. They took up room and they were never going to be used again. Fortunately some have escaped that fate. MovieArt has probably the most U.S. 24 sheets of any dealer. Many of the images of 24 sheets that you have seen at Heritage, for example, have been put together in photoshop for a seamless look. Linen-backing a 24 sheet would attempt to capture that seamlessness. Emovieposter photographs the whole poster much as they do their other posters and thus you can see the native folds more easily. Kirby McDaniel MovieArt Austin