a method of inspecting an oled device to locate and characterize defects in the registration of organic material transferred from a donor in swaths in response to heat produced by a multichannel laser print head includes optically inspecting the oled device after or during manufacture to identify the boundaries between swaths of transferred organic material , and determining if the swaths overlap at a seam of the boundary or if there is a gap between swath edges at the seam or if there is an offset between the edges of adjacent swaths .