Knitting Pattern Chart Maker

A knitting chart looks like graph paper with a code written on it, and most knitters first meet one with a small sinking feeling. The code is less strange than it seems. A chart is a drawing of the finished fabric, seen from the front, with one box for every stitch. Everything that confuses people about charts follows from that single decision.

Brooklyn Tweed’s tutorial puts it plainly: each cell is one stitch, each row of cells is one row or round of knitting, and the chart as a whole illustrates the right side, the public face of the work. The symbols are chosen to resemble what a stitch looks like from that side. A blank box looks like smooth stockinette. A dash looks like the bump of a purl.

One picture, two directions

If a chart is a picture of the front, then the knitter has to walk across that picture the same way the needles walk across the fabric. Knitting proceeds from the right needle tip leftward across the work, and it builds upward. So a chart starts at the bottom, and a right-side row is read from right to left. That much is easy to accept.

The trouble comes one row later. In flat knitting you turn the work at the end of each row, and now the back of the fabric faces you. You are still working toward the left as you see it, but seen from the front of the fabric you are travelling the other way. The chart does not turn over with you. It stays a picture of the front. So Brooklyn Tweed gives the rule in one line: right-side rows are read from right to left, and wrong-side rows from left to right.

The chart this tool prints carries a quiet reminder of this. It puts each row’s number at the edge where that row begins, so on a flat chart the numbers alternate. Row 1 is numbered on the right. Row 2 is numbered on the left.

Knitting in the round removes the problem. A tube is worked in a spiral with the front always facing out, so the knitter never sees the back. Every round is read from right to left, and Brooklyn Tweed gives the reason in one line: you only ever see the right side of your work when knitting circularly. On such a chart the tool puts every number on the right.

Right to left, then, is the home direction of a chart. The left-to-right rows are the exception, and they exist only because a flat piece gets turned.

What a symbol becomes on the back

Direction is half of the wrong-side puzzle. The other half is that a stitch has two faces. A knit stitch seen from behind is a purl bump, and a purl seen from behind is a smooth knit. A chart shows the front, so on a wrong-side row the knitter must make whatever stitch will look right from the other side.

This is why the Craft Yarn Council’s table of standard symbols does not define the empty box as “knit”. It defines it as “K on RS, p on WS”. The dash or dot is the reverse: purl on the right side, knit on the wrong side. Vogue Knitting says the same thing about its own symbol set: on right-side rows work the stitches as they appear, and on wrong-side rows work the opposite of what is shown. Brooklyn Tweed calls these chameleon symbols, which is a fair name for a mark that keeps its looks while changing its instructions.

The pairing runs through the decreases as well. In the Council’s table a right-leaning k2tog symbol is worked as p2tog on a wrong-side row, and the symbol for ssk is worked as ssp. A slipped stitch charted with the yarn held at the back is slipped with the yarn in front when the back of the work is facing, because the yarn has to end up on the same face of the fabric either way.

Not every publisher draws these the same way. The Council’s page says there is a wide variety of knit symbols in use and tells readers always to refer to the pattern key. An encyclopedia entry on knitting patterns is blunter: there is no single authoritative source for knitting symbols and abbreviations, so several standards exist. The Council’s guidelines exist to narrow that variety, and it offers its symbol graphics free of charge, asking for notice and a credit line when they appear in a publication. A legend printed beside every chart is still the knitter’s real protection.

Why the squares should not be square

Ordinary graph paper has square cells. Knitted stitches are not square. A picture knitted stitch by stitch is made of pixels that are usually rectangular, and how far they are from square depends on the gauge, the number of stitches and of rows in a given length. Take 18 stitches and 24 rows over a 4 inch square, the gauge the tool above starts with. That comes to 4.5 stitches per inch across but 6 rows per inch upward.

For a texture pattern this hardly matters, since the chart is a set of instructions and the fabric will be whatever shape it is. For a picture it matters a great deal. Draw a circle on square graph paper, knit it at that gauge, and the circle comes out squashed, because 24 rows only reach as high as 18 stitches reach across.

The correction is simple arithmetic. At 18 stitches and 24 rows to 4 inches, one stitch is 0.22 inches wide and one row is 0.17 inches tall, so each chart cell should be drawn one and a third times as wide as it is tall. A picture needs more rows than square cells would suggest, by that same factor.

Here is a case that can be checked in the tool above. Take a picture 400 pixels wide and 300 tall, and ask for a chart 60 stitches wide at that gauge. Square cells would give 45 rows. The right answer is 60 times three quarters times four thirds, which is 60, so the chart is 60 rows. A disc 200 pixels across in that picture covers 30 stitches, which is 6.67 inches, and 40 rows, which is 6.67 inches as well. On the 45-row chart the same disc would be 6.67 inches wide and only 5 inches tall.

The same two numbers give the finished size of any chart. Sixty stitches at 18 to 4 inches is 13.3 inches. None of it is worth anything, though, unless the gauge is the knitter’s own. Vogue Knitting advises working a swatch at least four inches square with the actual yarn and needles, and measuring again after the first five inches of the real piece. The Council labels its own gauge ranges for each yarn weight as guidelines only.

Color, floats and what a picture costs

Colorwork charts are the gentlest kind to read. Brooklyn Tweed notes that stranded motifs are usually worked in the round in plain stockinette, so every stitch is a knit and the only thing to follow is the color of each box.

What the chart does not show is the back. In stranded knitting the yarn not in use is carried behind the stitches being worked, and each carried length is a float. Brooklyn Tweed warns that floats pulled too tight pucker the fabric and floats left too loose can catch.

Length matters too, and tradition set the limit. Fair Isle patterns, by the usual account, use only two colors in a row and normally had no more than three consecutive stitches of any one color, because a long strand of the other is easy to catch with a finger or a button. The tool counts the longest float in every row and flags any that runs past three stitches. That is a habit of one tradition and no law. The same account speaks of avoiding loose strands longer than three to five stitches, so other knitters draw the line a stitch or two further out. A longer strand can be caught or woven into the fabric as it is carried.

A chart made from a photograph keeps no such habit. It will happily ask for a block of one color forty stitches wide, and no one should strand a second yarn behind that. Large areas of color belong to intarsia, where only one color is active on any stitch and no yarn is carried across the back of the work.

That is the honest limit of turning a picture into a chart. Reducing a photograph to a handful of yarn colors is arithmetic on pixels. It knows nothing about floats, about how many bobbins a row would need, or about whether two shades will read as different once knitted. The chart is a starting sketch, and it has to be edited by someone who knows how it will be worked.

Charts, words and counting

Written instructions and charts say the same thing in two notations. A row of ribbing over ten stitches can be drawn as ten cells, or written the way the Council’s guide to reading patterns writes repeats, with brackets around a group and a count after it: [k2, p2] 2 times, k2. The wrong-side row that follows reverses every stitch and the order, which gives [p2, k2] 2 times, p2. The Council’s guide has a homelier phrase for it: knit the knit stitches and purl the purl stitches.

Each form has its uses. A chart shows how stitches stack up, row over row, so a misplaced yarn over is visible at a glance. Words are easier to follow at a table without looking down, and they carry the count. Some patterns print the whole of their instructions both ways, because knitters prefer one or the other, and some mix the two, with words for the start and the end and a chart for the repeated design.

Counting is where both forms earn their keep. Every decrease uses two stitches and leaves one. Every yarn over uses none and leaves one. A lace row such as k1, k2tog, yo, k1, yo, ssk, k1 uses seven stitches and leaves seven, and that balance can be checked before a single stitch is cast on. When a chart changes width, publishers fill the gaps with “no stitch” boxes, which Brooklyn Tweed describes as placeholders that keep the columns aligned.

A row that leaves a different number of stitches than the next row needs is the commonest error in a pattern, and the cheapest to catch on paper. The chart tells you what the fabric will look like. The count tells you whether it can exist.