Late 20th century domestic/studio models typically use up to 200 latch-hook needles to hold the stitches in fine, standard, mid-gauge or bulky gauge needle. A carriage or cam box is passed across the bed of needles causing the needle movements required to produce each next stitch. By means of various selection methods, e. g. punch cards, particular needles can be caused to travel by alternate pathways through the cam box. Thus needles will knit or not, and the unknitted yarn portions will lie under (slip stitch) or over the needle or be held in the needle hook (tuck stitch). Needles can be placed in holding position to allow short row shaping. In modern machines, patterns can be obtained via either mechanical control, using punchcards, or electronic control, using computer software for patterning.