Flexo and Offset are the two most common print processes for envelopes. "Flexo" is short for Flexographic which means that the printing is done with a rubber or more commonly plastic printing plate which is flexible as opposed to a metal plate commonly used for offset printing. Flexo printing can be done as the envelope is being manufactured or "in-line". This saves time and effort versus offset printing which is a separate process from the actual manufacture of the envelopes. There is a qualitative difference between flexo and offset. Generally speaking, for jobs that contain screens, half-tones or fine lines, offset printing is required in order to acheive the best results. Flexo printing is usually reserved for simple line copy or basic graphic images and is most commonly done for long runs of 100m or more. Flexo printing is usually less costly than offset especially on the longer runs.