at some point in the hologram replication process, one or more metal shims need to be mounted around the circumference of a metal cylinder (the embossing cylinder). The point at which the shims join often produces a visible line in the resulting embossed film. This line is most objectionable where the finished result is intended to be a continuous pattern. Those skilled in the art have developed procedures which successfully minimise or even eliminate such optical discontinuities in the final product.
