Hand knitters employ several techniques for increasing the number of stitches in a row or round of fabric. Instructions for The order how to knit a Hose, published in 1655, make several references to widening a row. Procedural instructions appear regularly in Victorian publications beginning with The Ladies’ Knitting and Netting Book, from 1837. This describes two methods that remain in practice, both working the added stitch into a loop in the preceding row.
The Workwoman’s Guide, from 1840, notes that “increasing the number of loops is generally done in the middle of a pinful of stitches.” It adds to the “various modes of widening” with one “effected by taking up the cross loop, below the next stitch, belonging to the row before, and afterwards continuing the plain knitting.” That cross loop is a central theme of this post and is examined in detail below.
The process of casting on a row of loops at the outset of a piece of knitted fabric is also relevant to this discussion. The first published instructions for it appear in The Knitting Teacher’s Assistant, from 1817. This is framed as a Q&A dialog between a teacher and student. It was retained verbatim in subsequent editions and can be seen in this one from 1881. The book makes no mention of increasing the stitch count in subsequent rows. However, the described cast-on technique simply places a closed loop on the needle and can be applied at any point in the fabric. It is now often termed a “backward loop” or “e-wrap.”
The first illustrated instructions for an increase appear in the The Knitting Book, published in 1847 by Eleanore Riego de la Branchardière. She describes an increase worked into the segment of the yarn or thread between the loop just knitted and the one that is about to be. When lifted up from the preceding row, that segment is the “cross loop” noted above.
It is termed a “sinker loop” in the formally standardized vocabulary of mechanized industrial knitting, in contrast to the “needle loop” (both named for parts of the machine). There has never been any generally accepted term for the former in the glossary of hand knitting, and it is referred to variously as the strand, yarn, or bar between the loops.
When describing other types of looped fabric, the transition from the leading leg of one loop to the trailing leg of the next is termed a “lag.” It is shown here in the context of knitting, highlighted in black.

The same knitted structure is formed by the forward pass in many Tunisian crochet stitches but has no direct correlate in ordinary crochet. In that craft, as well, a stitch is begun by pulling a vertical loop through the one below it. However, it is then joined to the adjacent loop in the preceding row to complete the stitch. Nonetheless, reference to the dichotomy between loop and lag can ease the comparison of looped structures that are typically associated with one craft but on closer examination are seen to be shared with others.
Riego terms the process of converting a lag into a knittable loop “to make a stitch.” There are two methods for doing this. In the one rather cryptically described in 1840, the lag in the preceding row is twisted into a closed loop and a new loop is knitted through it.
The other, as described by Riego, extends this over two rows. It is seeded with a “yarn over” in the first and completed in the second. This approach permits a number of stitches to be made consecutively. The remark that “it will form an open stitch” also implies that Riego recognized twisted stitches as an element of knitting.
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TO MAKE A STITCH
Bring the thread forward between the pins; when this stitch is worked into the next row it will form an open stitch.
TO MAKE TWO, THREE, OR MORE STITCHES
Turn the thread as many times around the pin as E, F, G, and in the next row; pearl a stitch and knit a stitch, alternately, taking off one turn of the thread each time, for as many stitches as were made in the row before.

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The facility of adding a number of consecutive loops is also provided by the simple cast-on technique described in 1817. The closed loops it produces, like those made by lifting the lag, result in increases that lean to the left or the right in the fabric. Since that directionality is determined by the closed segment of a made stitch, a brief digression may be useful.
The atomic component of all forms of looped fabric is, by definition, the loop itself. It is shown here in its closed form with both an “S-twist” and “Z-twist,” describing the way the legs of the loop cross by analogy to the central diagonal segment of the respective letters.
There is also a zero-twist “open loop” shown in the first illustration above. All forms become comparable by taking the definitive attribute of a loop to be either that its legs cross, or are held together by the point in the preexisting fabric through which the loop is drawn.
A lifted-lag increase leans to the left or to the right in the fabric depending on whether it is twisted into an S-loop or a Z-loop. The corresponding factor in the two-row technique is the path the thread takes around the needle in the yarn over. Riego’s illustration shows it wrapped in the customary direction for her style of knitting. In current parlance the opposite direction is termed a “reverse yarn over.”
All yarn overs in a consecutive run are wrapped in the same direction. However, when dispersed in the fabric, individual and sequential yarn overs can be wrapped in opposite directions. It is also possible to interpose closed loops in the wrap. The flexibility of made increases is demonstrated by Roxanne Richardson in a tutorial video, also discussing differences between the single-row and two-row approaches. She presents the backward loop cast on in a separate video, including its use for adding loops to subsequent rows.
Riego also describes the spiral yarn over in her instructions for a treble crochet stitch (UK). It is a definitive element of all tall crochet stitches, with a triple wrap generating the quintuple form. The path the yarn takes around the hook is opposite to that seen in the illustration of knitting but crocheters also call it a yarn over. It is abbreviated YO in both cases.

When crochet instructions specify the non-default direction, it is generally labeled a “yarn under.” The knitter’s term “reverse yarn over” also appears in crochet instructions but designates yet another alternative. As already noted, in contexts such as the present, it would be quite useful to have a normalized terminology for describing shared elements of the two crafts. I’m therefore going to digress into that matter for a second time.
The concepts of S-twist and Z-twist introduced above are probably most familiar to yarncrafters as used to designate the way yarn is spun and plied.

The spiral around the quintuple crochet stitch is readily seen as an S, as is the corresponding wrap on the hook. The spiral on the knitting needle in Riego’s illustration of how to make stitches is a Z. Any potential ambiguity resulting from the point of view can be eliminated by stipulating that the S/Z attribute of the wrap is relative to the hook or needle when held vertically. (The same proviso applies to spinning, where the point of view is normalized to that of a drop spindle holding the yarn vertically, rather than a spinning wheel where it is held horizontally.)
The two wrap directions appear in both knitting and crochet. Instructions for stitch production and separate yarn overs can therefore require clarification of the intended direction in either context. This is often done by specifying a clockwise or counter-clockwise wrap but there is no consensus about the point of view for that reference. The need for such specification can be minimized by replacing the ubiquitous but ambiguous procedural YO with an explicit structural YS or YZ. This would also subsume other labels for yarn wraps that might require further specification, beyond indicating whether the yarn is held in front of or behind the work, which is prescribed separately in any case.
Knitting would have been the loopcraft with which readers of the introductory descriptions of crochet had the greatest prior experience. If it is safe to posit that the transition from shepherd’s knitting to modern crochet was driven even in part by innovative knitters applying their skills to the elder craft, the extended spiral yarn over is likely to have been among the transferred techniques.
Tunisian crochet emerged in that shared environment, absorbing elements from and contributing to the further development of both knitting and ordinary crochet. A separate post presents what I believe are the earliest instructions for tall-stitch Tunisian crochet. Concluding the present one with another cast on for knitting, instructions from 1864 start with a directive that appears to have been taken directly from Tunisian crochet, which by that date had become enormously popular.
“Make a chain with a crochet hook of one hundred and fifty stitches, then take up each stitch on a large wooden knitting-needle, and knit plain…”
So interesting to see you propose YS and YZ as preferable ways to denote directionality of a YO. I’ve been thinking a lot about S- and Z-plied yarns lately and how to explain (to other knitters) about how twist is added or lost based on the combination of knitting style and direction of ply. The difficulty in using clockwise/counterclockwise to describe the direction is definitely problematic. I had just this week thought that pointing out the \ or / direction of the yarn on the needle as S or Z would be a good way to do that, i.e. an S-ply yarn with S-rotation of working yarn adds twist, while Z-rotation removes it. I really appreciate logical ways of describing how knitting works so that knitters can understand better what they are doing. (And, hey, thanks for the link to my videos!)