Sometimes in knitting you need a double increase that doesn’t lean either to the left or to the right… Enter the Central Double Increase. You start with one stitch and turn it into three, increasing your stitch count by two, and it all ends up perfectly balanced, ideal for symmetrical stitch patterns.

Our free Vintage Chevron Blanket knitting pattern in Till uses this technique, and we demonstrate using a swatch of that project in our Central Double Increase Tutorial video below!

Video Tutorial: Central Double Increase (CDI)

Click To See Video Transcript

Hi, this is Whitney from Purl Soho, and I’m going to demonstrate the Central Double Increase.

This increase starts with one stitch and ends with three, which increases your stitch count by two stitches. It doesn’t lean right or left, so you’ll often find it going up the middle of a stitch pattern, like here in our Vintage Chevron Blanket. You work a Central Double Increase every other row to create the spine that runs up each chevron. It’s very distinctive and you can see that it’s well balanced. It’s not leaning to the right or the left.

So now let’s work a Central Double Increase and you can see how to do it. I have a swatch here of our Vintage Chevron Blanket stitch pattern, and I’ve worked to the place where I need to make that Central Double Increase.

So I’m ready for the first step, which is to knit through the back loop of the next stitch. So to do that, you insert the right needle into the back leg of that stitch. You bring your working yarn around like you do for a normal knit stitch, and pull it through. Now, instead of allowing that stitch to fall off the needle, leave it there, ready for the next step, which is to knit through the front leg of that same stitch. So insert the right needle into the front leg of this stitch, wrap the yarn around, pull it through, again like a normal knit stitch, and this time allow the stitch to slide off the left needle.

So you can see that out of one stitch, we have created two stitches here on the right needle. One more to go. So now you’re going to locate this vertical strand that is coming down between these two stitches. It’s right here, this vertical strand, and you’re going to insert your left needle from left to right under that strand and lift it onto your left needle. And now to finish, you just knit this stitch through the back loop. So insert the right needle into the back leg here like that, wrap your working yarn, pull it through, and allow this stitch to slide off the left needle.

So now you can see that here we have three stitches, all created from one stitch, and that the increase doesn’t lean right or left, so that’s pretty cool. And that’s how you knit a Central Double Increase.

Step-By-Step-Instructions: Central Double Increase (CDI)

Here are step-by-step written instructions for the Central Double Increase to guide you from one stitch to three!

Central Double Increase (CDI) | Purl Soho

Start by knitting through the back loop of the next stitch, inserting your right needle into the back leg of that stitch, bringing your working yarn around as for a normal knit stitch, and pulling it through… But instead of allowing that stitch to fall off the needle, leave it there, ready for the next step.

Central Double Increase (CDI) | Purl Soho

Now knit through front loop of that same stitch (like a normal knit stitch!), and this time, allow the stitch to slide off the left needle. Out of one stitch, you now have two stitches on the right needle, and it’s time to make one more!

Central Double Increase (CDI) | Purl Soho

Locate the vertical strand between the two stitches you just created. In the photo above, the arrow is pointing right to it!

Central Double Increase (CDI) | Purl Soho

Lift that strand onto your left needle, inserting your needle tip from left to right, as shown above.

Central Double Increase (CDI) | Purl Soho

Now knit this stitch through the back loop, inserting the right needle through the back leg, and allow it to slide off the left needle.

That’s it… Two stitches increased and the remaining stitches remain perfectly centered. No leaning here!

Practice The Central Double Increase!

Put what you learned in our Central Double Increase Tutorial to work with our free Vintage Chevron Blanket pattern!

Central Double Increase (CDI) | Purl Soho

You’ll use the Central Double Increase (CDI), paired with Slip, Slip, Knit, Pass (S2KP) decreases, to make those simple chevron shapes, with the CDI forming a spine that runs up the center of each chevron… Very cool!

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