A length of web material is worked by a number of individual work units each of which performs a work function on the material to progressively achieve an end result, the work units being arranged serially along an X coordinate direction extending lengthwise of the web material and the web material being moved unidirectionally by each work unit. Accumulators are provided between adjacent ones of the work units and one or both of the work units located immediately on opposite sides of an accumulator are controlled in response to the amount of slack web material contained in the accumulator, as by stopping the feeding of the web material by the upstream one of the work units when the accumulated slack material exceeds a given amount and/or by stopping the feeding of the web material by the downstream one of the work units when the amount of accumulated material falls below a given amount. The work units may be a number of printers for printing end graphics onto the web material and a following cutting mechanism for cutting the end graphics from the web material. The end graphics may be multi-colored ones with each printer printing a color separate portion of the end graphics.