Flattening

“Wave”, “ripple”, “cockle”, and “belly” are all terms used to describe planar distortions in paper. These disturbances can occur when a sheet of paper is exposed to humidity or improperly handled when fit in a frame.  Direct contact with water or simply a humid afternoon can cause paper to warp.  Improper hinging during framing or a frame that does not allow the paper to expand can also induce distortions.  Whatever the cause, this condition can often be corrected by re-humidifying the sheet and drying it between paper blotters and holytex under pressure.