Our office has used the Avery 5366 labels for many years with no problems...until they came out with the True Block Technology. These are by far the worst labels we've ever used. They simply do not stick to any type manila folder. This is a nightmare when retrieving folders only to find the labels have fallen off within days of adhering them! Needless to say we trashed our stock of Avery labels and are using another brand. Avery needs to either bring back the previous labels or resolve the adhesion problem with the True Block.