Rack of ribs

I like to swatch.  Currently, texture is my most favorite element to experiment with in my swatches. I'm not talking about yarn textures, though I pay great attention to selecting the yarn, as most knitters do. I'm talking about constructed textures that are created using various knitting stitches and techniques. These textures are often most striking when using a relatively smooth yarn.

I was delighted, when not long after I joined Twitter (I'm @ojollyknits.), I had two inquiries about the stitch pattern (See swatch #1.) that I was using as a background on my Twitter page at the time.

Swatch #1

One person suggested that it had a crochet-like quality. This swatch, however, was created on a Passap knitting machine. The stitch pattern uses two texture-building techniques, racking and tucking.

Racking
Simply put, if a knitting machine has two beds of needles (like this, for instance) knit stitches are easily created on each side of the fabric. Alternate columns of knit stitches on each side of the fabric and you've got ribbing. (One side's knit stitch is the other side's purl.) Racking is the act of moving one knitting bed laterally in relation to the other. Newly formed stitches are pulled to one side. When the next row is knitted, the knitting order of the stitches has shifted and the pull to the side becomes knitted into the fabric. In Swatch #1 above, the columns (or wales) of knit stitches are not vertical as in normal ribs, but wavy.  It's the result of racking to the left, knitting a few rows, racking to the left again, knitting a few rows, racking right, knitting a few rows, racking right again, and then repeating the whole racking sequence.  Each rack pulls the wales off vertical, until they are brought back to neutral and then pulled in the opposite direction. A more straight-forward example of racking, without the crazy tucks, can be seen in swatch #2.

Swatch #2

Tucking
This link (Link is no longer available. ed. OJ 11/5/2011) provides great diagrams of  how knit stitches are formed on a knitting machine.  A tuck is another creature however.  It's created when yarn is held in the hook of a needle that's already holding a loop.  Both the old loop and the new yarn (the tuck) stay in the hook, but are not knitted in that row.  In hand knitting this is referred to as "knit one below" and is achieved by knitting into a stitch that is one row below the current row.  The unworked stitch above is then dropped forming the "tuck."  Hand knitters use this method when doing a brioche or fisherman's rib.

The more tucks, the more texture, but alas, one cannot tuck indefinitely.  Eventually the tucks collecting on the needle of a machine must be knitted off, and when hand knitting, one can only reach so many rows below.

Tucking creates all sorts of distorted stitches in the fabric.  (Distortion is my friend. ;))  The stitch below the tuck elongates, because it is pulled all the way up to the next knit stitch, which may be several rows above. This makes the adjacent stitches smaller. It also pulls the wales off-center, though generally not as much as racking does.

Swatch #1 detail

An infinite number of stitch patterns can be created using combinations of racking and tucking. Explorations in racking and tucking and many other machine knitting techniques can be found in A Machine Knitter's Guide to Creating Fabrics by Susanna E. Lewis (one of my former teachers) and Julie Weissman. I highly recommend the book.  Sadly, it's now out of print and difficult to find.

But I do encourage experimentation!  Here are some tips:

• When racking, make sure the stitch size is large enough to accommodate the pull.  
• Don't forget to knit off your tucks.  Three or four tucks is probably the very most your equipment can handle. 
• Try experimenting with tucking two or more adjacent stitches.  
• Although I used rayon in these swatches, it's sometimes easier to work with a more elastic yarn, like wool.

It's true that knitted "things" are nice, but remember to enjoy the process; sometimes a cool swatch is a worthy goal.

Many thanks to Ravelry members, KerstinGermany, Bufordsmom, and yarnsplitter, three machine knitters who helped me with some of the hand knitting terminology in this post.

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Edited to update Twitter name 28July2013