A crocheter named Sandra emailed me last week about swatches in a 2008 blog post. It turns out that these swatches were my earliest TEKSplorations. I thought this stitch already had its own newsletter issue to which I could refer her, but I've found only mentions of it over time.

 

It’s likely you’ve tried the Teks. It's also possible that you've breezed past it in crochet books, where it tends to look unglamorous. (You can see what I mean in my newsletter issue #26, Fun With Blocking.) 

The Teks is an easy stitch to crochet for creating fast gossamer lace and thick warm fabrics. Shakti Scarfythings (montage, upper right) is a tribute to warm Teks on the bias. Let’s add that "E" to TKS with a stitch how-to:

Tunisian Extended Knit Stitch (Teks): Insert hook from front to back between both vertical bars and under all horizontal bars of designated stitch (sometimes called "knitwise"), yarn over and pull loop through to front: this is a Tunisian Knit Stitch or "Tks"; then ch 1. The ch-1 turns a Tks into a Teks. 
 

Regarding its name, here’s how I introduced the Teks in A Powerful Tunisian Crochet Stitch to Love (Dec. 2011): "For all its power, this Tunisian stitch doesn't seem to be one of the basic stitches one learns after the Tunisian Simple Stitch (Tss), even though it's easy to do. It has no standard name or description. I've seen it called Knitwise Extended Stitch, Corded Stitch, Tunisian Knit Single Crochet, Tunisian Shaker Stitch, and 'Tunisian Knit Stitch with a chain-1'."

Calling it “Teks” has been working well for me; it even hints at similar stitches to play with: TES (an extended TSS), TEES (TSS with ch 2), TEEKS (TKS with ch 2), etc.

The Tech of TEKS Effects
(see why I like the name?)

This simple, unique stitch is a wonderland of subtle and special effects. When I chain 1 to complete the stitch (i.e., turn a TKS into a TEKS), the loop that would have remained on the hook now behaves as if it’s “dropped” (to borrow a knit term). In crochet terms, even though the way you crochet it is like a non-Tunisian “extended” single crochet, it behaves as if you crocheted a slip stitch and then pulled up the loop to tighten it. (Using a big hook and blocking later reveals this.)

These two beige filet-like Teks swatches show how the front (left photo) and back (right photo) look so nice that I think of it as reversible: rare for a Tunisian fabric!

When I'm not glamming up a Teks veil with sequins, I think of the stitch more as a design ninja for adding joints (i.e. DRAPE), spacers (i.e. DRAMA), and measuring out extra ease (i.e. STRETCH). The Rivuline border (last photo on left) Has Teks in it for all 3 ninja reasons.