What size were the "colored glossy photographs" described in the song "Alice's Restaurant Massacree" by Arlo Guthrie ?

This song was released in September, 1967 on Warner Brother record label and hit #17 on Billboard chart. It was 18 minutes and 34 seconds long and was the complete side A of the album. It was written based on a real incident that Arlo had perpetrated on Thanksgiving in 1965, in that he had dumped trash and was given a citation for littering. He subsequently was rejected by the army draft due to the citation for littering. In 1969 it was made into a film of the same name. The song states there were 27-8x10 colored glossy photographs.Several radio stations used to play this song every year on Thanksgiving. Although the lyrics have a couple of lines that may not be appropriate for younger listeners, it is a funny song.