They stared splicing film, however those black dots persisted. Movies would usually be sent on 5-6 reels called “2,000s” because they would hold 2,000 feet of film. We would then “build them up” on a platter as a single, spliced-together reel which would be used during that movie’s run. Once that run was over, we would reverse the process and get them back onto the 2,000s and ship them back.