SSP & SSSP Knitting Decreases
Knitting decreases are used to reduce the total number of stitches on your needles; usually by 1 or 2 stitches at a time.
The ssp and sssp decreases are the purl equivalents of the ssk and sssk decreases.
Whereas the ssk and sssk are carried out on a knit row, the ssp and sssp are carried out on a purl row.
ssp = Slip one, slip one, purl slip stitches together.
This is a single decrease, so it reduces the number of stitches on your needles by 1.
sssp = Slip one, slip one, slip one, purl slip stitches together.
This is a double decrease, so it reduces the number of stitches on your needles by 2.
Both of these decreases are left-leaning, so from the front of your knitted work they will appear to lean slightly to the left.
This is why in knitting patterns you may see the ssp and sssp decreases on the same row as p2tog or p3tog decreases which are right-leaning.
Combining a right-leaning decrease with a left-leaning decrease gives your knitting a more balanced & symmetrical appearance.
And here is the video tutorial to show you exactly how they're done:
For these methods, the yarn always stays in front of the needles i.e. between you and the needles.
To begin an ssp, you slip a stitch knitwise, and then slip another stitch knitwise.
You then transfer those 2 slipped stitches back onto the left hand needle.
The steps so far have ensured that the 2 stitches are orientated in the correct way for this method to work.
As a last step, you will need to purl those two stitches through the backs of the loops (p2tog tbl). You take the right hand needle up through the backs of the 2 stitches and then purl them together into 1 single stitch.
You will now have 1 less stitch on your needles than before.
The sssp is very similar except you slip 3 stitches knitwise, rather than 2, and you purl all 3 together through the back of the loops (p3tog tbl).
The purling through the backs of the loops is definitely an awkward step so don't worry if you struggle with it. Both the ssp and the sssp are fairly uncommon, but when they do crop up, you'll now know what to do!
Thanks for watching :)