The CDD (centered double decrease) is a basic decrease that you should know how to perform. It’s used in A TON of knitting patterns – raglans and lace knitting are just two examples.
The basics are simple – this stitch decreases by two stitches – one on either side of the center stitch. There are other decreases that reduce the count by 2, so don’t confuse this decrease with any of those.
The centered double decrease can be abbreviated a few different ways. The most common are: CDD and S2KP (slip 2, knit, pass (2) stitches over). Given there is more than one, it wouldn’t surprise me if you come across others. But, the stitch is always worked in this same way.
On a Chart
It might vary a bit depending on the charting software the designer uses, but the symbol will likely look something like this:
How to Work the CDD
Step 1: Slip 2 stitches as if to work a k2tog. Note that you’re slipping these 2 stitches at the same time. This part is crucial.
Keep in mind that you’re not working these stitches – just slipping them AT THE SAME TIME. Yes, I said that already – but that’s because it’s so important.
Step 2: Knit 1.
See how the 2 sts you slipped are intertwined on themselves? Don’t worry about that – it’ll actually help you in the next step.
Step 3: Pass both slipped stitches over the knit stitch. Pass them together – trying to separate them will be next to impossible and you’ll stretch one of the stitches and it will look funny.
This means you’ll be passing both stitches 2 and 3 that are on the right needle, over stitch 1 that’s also on the right needle.
Once you’ve done these steps, you’re done!
After you’ve worked several of these stitches above each other, you’ll have a nice little line like we do here.
Note that this decrease creates a column of raised sts (it’s the center stitch of your decrease – the stitch on the left of the 2 you slipped together). If you don’t want this, you might want to consider the sl1, k2tog, psso decrease because the center stitch will be underneath. No pesky columns!
Also, as you can see from these swatch pics, working the CDD creates a nice little zig zag effect. Because of this, it’s often used in chevron patterns.
Give the CDD a try – it’s not hard and it’s a great stitch to know how to work.
A free pattern
Our Hike to Marion Falls Shawl uses the CDD to beautiful effect! Give it a try!