It also used the same alloy as Linotype machines, so was a useful adjunct to page makeup for newspapers as, when complete, all the metal could be remelted without having to be separated or the type from the headings redistributed back into case. The success of these machines lay in different fields. The Monotype caster was more popular for bookwork that required the ability to make manual corrections and edits while the slug casting systems found success in newspaper production where speed of production and 'make ready' for print was essential. There is another essential difference between Monotype and all the "slug"-producing machines – a Monotype machine functions with a minimal set of matrices. Each character needs one matrix. Linecasters cannot function this way, and these systems need quite large magazines of matrices to be able to set a complete line of text with the usual character repetitions. Indeed, the nominal 90 channel magazine of a linecaster really has 91 total channels, with the first two channels allocated to the lower case 'e', and with these matrices being alternately selected from channel 0 or channel 1, for alternate lines of cast type. Additionally, Monotype must use a punched paper tape, and the "reading frame" is always backwards (right-to-left) in order to achieve justification, as justification is not an inherent capability of the machine (however, "flush left" is an inherent capability). Whereas Linotype may use a punched paper tape, although this option is seldom-used outside of daily newspapers, and whether a tape is used, or not, the "reading frame" is always forwards (left-to-right), with justification being an inherent capability of the machine (and, "flush right", "centered" and "flush left" may be very easily accommodated manually, or automatically using a "quadder" attachment). Linotype The key feature of the Linotype is the use of molds which circulate through the machine in its various stages of operation. One type is a space band (a special two-part sliding wedge) and the other is a letter matrix made of brass. The matrices are stored in one or more magazines on top of the machine (providing the operator with a choice of fonts; these can also be exchanged with other extra magazines as desired) while the space bands are stored in a box closer to the keyboard. Once a key is pressed, the matrix passes through what is known as the ‘assembler front’, down past a rotating