Abstract: An envelope with a pressure sensitive seal containing a hidden printed message which is revealed when the seal has been opened. The unsealed edges of the envelope each have an anchor coating, and the message is formed by voids in the anchor coating on one edge. Cohesive layers adhere to the anchor coatings on both edges, and seal the envelope as desired. The cohesive layers have a stronger affinity for each other than for the anchor coating with the void regions, and so the message is revealed as the cohesive layer separates from the void-containing anchor coating when the sealed envelope is opened.

Abstract: An envelope with a pressure sensitive seal containing a hidden printed message which is revealed when the seal has been opened. The unsealed edges of the envelope each have an anchor coating covered by a cohesive layer. The message is formed by voids in the cohesive layer on one edge. Cohesive layers adhere to the anchor coatings on both edges, and seal the envelope as desired. The cohesive layers have a stronger affinity for each other than for the anchor coating. The message is revealed as the cohesive layer containing voids separates from the anchor coating causing the disruption of the anchor coating, when the sealed envelope is opened.

Abstract: A printing method and apparatus for printing different indicia, such as account numbers, on selected documents without changing plates or stopping the press during a press run. Different indicia are provided at two or more lines on a printing plate, each line being separated from an adjacent line on the plate by a predetermined distance relative to movement of the plate in a press. The plate transfers images to a blanket having a region that does not contact the plate and thus receives no image of the plate area that registers with the noncontacting region of the blanket. The plate and blanket initially are aligned so that the noncontacting region registers with one set of indicia on the plate, so that the blanket receives a partial inked image lacking that indicia. That partial inked image is transferred to sheets passing through the press.