Sunday, November 22, 2015

Picking up stitches along a selvedge

Getting live loops where there are none requires you to pick up stitches. But what does "picking up stitches" mean? Part of it depends on WHERE you are picking up stitches.  Per the below diagram, one common type is picking up along a vertical edge.  This is called picking up through a "selvedge" (sometimes spelled "selvage" or "selvedge") and is the subject of this post, which is the first in a series.

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As you see on the below schematic of a cardigan sweater, the most common place for a vertical selvedge pick up is along the "long edges" of a cardigan sweater, in order to knit the button bands (shown in darker green, below).

The different types of picking up--today's post is about picking up through the vertical (dark green) "selvedges" which are the "long" fabric edges on this schematic of a cardigan sweater. Future posts will show horizontal and combo pick-ups. 

There are two methods of picking up stitches along a selvedge.  The first, called the fabric method, involves actually picking up loops out of the fabric itself. The fabric method comes in two versions: the every-single-row version and the every-other-row version.

Here are several illustrations: the first shows the every-single row version.  In this method, you pick up one arm of every stitch along the selvedge.  This is done by tracing up the first full column of knitting, and pulling onto your knitting needle, the innermost arm of each stitch in that column.

As you might imagine, this is a fairly primitive process. There is little slack in these edge stitches, and after catching the first one or two stitches, brute force is required to squirm the loops up onto your knitting needle.

There are several tricks you can use.  A very slim dpn helps to park the loops upon.  Another variation is called "pick up and knit" where you park only one or two stitches on the holding needle, then knit those off right away, and then pick up another one or two. Obviously, pick-up-and-knit gives the same end result as picking up the stitches first, and then knitting them all off at the same time--it's just easier, slack-wise, because knitting each stitch AS you pick it up allows for more slack at the time of pickup as only a stitch or two has to be dragged up to stretch all the way around needle. Yet, whether you use a slim dpn or the pick-up-and-knit trick, pulling every stitch right out of the side edge distorts and stresses the underlying fabric, and I would not recommend it.

The second, somewhat more refined version of the fabric method involves missing a row, then picking up a loop, and repeating this process, so you get a loop on every other row.  This fits with the actual structure of knitted fabric better--if you have a knit selvedge, the edge generally falls into a pattern of a longer loop paired with a shorter loop, you would (obviously) pick up the longer loop onto your needle. This is something of an improvement over the every-single-row method: with more slack, there is less stretching and stressing of the underlying fabric, less brute force.

If you are running a slipped selvedge, where one edge loop spans two rows, you might want to consider ignoring the actual loops of the slipped selvedge.  They are so large, the danger is that they'd get stretched out if you used their arms to pick up onto the holding needle.  Instead, consider moving in to the first full column past the selvedge for your pickup.

The second method of picking up stitches is called the added-yarn method.   In its classic incarnation, it is worked by holding a yarn behind the fabric.  As illustrated below, you then reach between the arms of the first full column of knitting with your crochet hook and fish forward a loop. Each loop is parked onto a knitting needle as it is formed.  Some knitters prefer to draw the added-yarn loop up into the space between the first and second full columns of knitting.  If you prefer that method, you'd draw up loops by inserting the crochet hook as the two red dots at the top of the illustration indicate.

The added-yarn method is rather more respectable in knitting circles than the fabric method, because this added-yarn technique does not distort the underlying fabric. Further, the line of yarn traveling up the entire length of the selvedge helps spread stress evenly along the column of knitting, which cannot be said for the fabric method.

There is another added-yarn method which is much better for picking up when you are planning to knit a layer of fabric, such as a facing.  Since, I have already written an entire post about my "beautiful method" I won't repeat that here, but if you go and look, I'll be waiting here when you return.

Given the amount of stress and distortion of the underlaying faric, the every-single-row fabric method is probably one to avoid.  But, for a quick item which receives no stress or tugging (edging on a neck scarf muffler) the every-other-row method works well enough.  In fact, if you do this enough, you get to where you can simply knit right through the edge loop without even bothering to anchor it on a knitting needle first--a true "pick-up-and-knit" trick.

Yet it is undeniable that, from a structural--and even from an aesthetic viewpoint, the added yarn method is all-around better: less stress and a prettier back-of-fabric.  For the front bands on an adult's cardigan sweater, which get tugged all the time and which are always on display, the added-yarn method is really going to be better. For this high-end use, I would not use the fabric method.

Now we come to the question of the RATE of pickup.  In a nutshell, the problem is that stockinette (the most common knit fabric) is not square.  A typical gauge in worsted weight yarn is 5 st/in, 7 rows/in.  If you attach two such fabrics to one another via picking up stitches along a selvedge, you can see the mismatch which will occur between rows and stitches.  In other words, if you pick up at a rate of 1:1 (one loop per row) you will get 7 loops where you really need only 5.

The blue square and the red square are both knit in stockinette,
but they are 90 degrees offset.  You can see the mismatch
between the row and stitch gauge where they adjoin.
The gray arrow shows the direction of the knitting on each square.

So, how to adjust the rate of pickup? There are many different opinions about this.  I think probably the most common trick is to simply skip rows on the pickup process. So, if you were using the added yarn method, with a 5-stitch:7-row pickup ratio you would skip drawing up loops in 2 of every 7 rows.  This would bring your live stitches on the needle to the exact number you need for a 5-st/inch gauge.

However, IMHO, this is not the best approach.  If you think about it, skipping rows makes for an uneven gappy edge, and the underlying fabric will respond by flaring or puckering.

I myself would strive for the most even pick-up possible.  Once I had my loops live, I would then worry about my gauge.  An even pickup followed by an increase or decrease has less of a gapping problem because the foundation, at least, is even across the underlying fabric.

With the every-other-row fabric method, I would be picking up only 3½ stitches per 7 rows, or more realistically--since I can't knit ½ stitches--I am picking up 7 stitches per 14 rows.  This is lower than my target rate of 10 stitches picked up for every 14 rows. (basic algebra--I hated it too--says 10 st picked up for 14 rows is the exact same as 5 stitches picked up for 7 rows.) So, I must INCREASE the number of loops on my needle.  In the first row (the one I am going to knit into the fabric selvedge loops) I will make this adjustment.  Into every group of 7 stitches on my needle, I will add three, more-or-less evenly spaced loops via the backward loop method (or any other increase you like).

The spacing isn't even, I fudged the spacing
to be able to illustrate two increases

With the added yarn method, I would pick up through every stitch.  Obviously, I will get one loop per row, a 1:1 ratio. At this rate of pickup, I will have 7 picked-up stitches on my needle for every seven rows, but I really want to have 5.  So, I will have to DECREASE the number of stitches on my needle to get to a target pick up rate of 5 loops picked up per 7 rows by getting rid of 2 stitches per group of 7. On the first row I will knit right after the loops have been picked up, I will work the decreases: k2tog's or ssk's are very handy and easy decreases to use, and I will space the two required decreases more-or-less evenly across each group of 7 stitches.

If you are knitting BANDS, an even better trick (imho) is to sufficiently change the GAUGE of the knitting you are going to add on the newly-picked-up stitches, so that this new knitting is at the natural pickup gauge of 1:1.  With the added-yarn method, this means you need not decrease. With the every-other row fabric method, you would double your number of stitches by k1, m1 in the first row to get to the same 1:1 ratio as added-yarn method (one stitch picked up for each row of selvedge).

The band-facing is picked up
via the "beautiful" method,
which is an added-yarn technique. 
In fact, changing gauge is what I myself nearly always do, especially with front bands on a cardigan, and here is why.  The gauge of knitting suitable for the body of a garment is much looser and stretchier than the gauge suitable for the front bands of a cardigan. The front bands should be knit more tightly (and it wouldn't hurt the cuff, neck or bottom bands of a garment to be knit tightly, either). If you adjust your needles down far enough, and knit tightly enough, the change in gauge makes the 1:1 pickup rate work.

In my experience, this tighter gauge and a 1:1 pickup rate yield a very professional result for knitting bands on picked up stitches.  See for yourself: at left is a photo of a front band-facing tightly knitted at right angles to the main fabric (showing on the purl side) on a 1:1 ratio of picked-up stitches.  Although this band-facing is on the inside of the garment, it is the same idea as a band which would be seen on the outside of the garment. As you can see, the knit stitches line up straight across from the purl stitches of the main fabric, even though the knit stitches were picked up and knit at right angles. By going down several needle sizes, the band-facing was knit tight enough to make its stitch gauge identical to the row gauge of the underlying fabric.

I will leave you with an aside on garter stitch which has the unique property of being "square,"  For this reason, it is a very good choice for modular knitting, which often features attached squares, triangles or strips at various angles to one another.  In the context of picking up stitches, garter stitch is naturally picked up and knit at a 1:1 ratio without having to perform any tricks at all.  However, as The Provisional Kitchener states in the comments, this is only an APPARENT 1:1 ratio, it is actually a 1:2 ratio because garter has "got as many stitches as ridges in a square - one ridge being made up of two rows. Which means you pick up one stitch every second row (which is every ridge)."(Thank you PK, for this good catch!)

Good knitting

You have been reading TECHknitting on picking up knit stitches along a selvedge, (also spelled selvage and selvedge, go figure!)