Men's Knitted Slip Stitch Slippers

These are made with double strands of yarn. I made them that way for my husband as he tends to wear the bottoms out quickly of slippers made in only one strand. Works up fast. 

MATERIALS
Yarn: 2 balls of 4 ply worsted weight yarn in black, two balls of 4 ply worsted weight yarn in blue. You can use any color combinations that you want. I bought large balls of yarn so I am not sure how much I used but I had lots left over.
Needles: 6 mm, either double pointed or circular. I like the circular needles as I find them easier to work with.

Gauge: 3 sts = 1 inch, 4 rows = 1 inch.

Size: These are men's shoe size 9. They will be very easy to adjust for smaller and larger sizes. To keep in pattern, add 4 stitches. This will increase the width just a little over 1 inch. For the length, to increase 1 inch work 4 more rows, to shorten the length by 1 inch leave off 4 rows.

Abbreviations used:

sts - stitches K - Knit P - Purl sl2 - slip 2 stitches (all stitches are slipped "purl wise", that is "as if to purl", but instead of doing the purl, simply move the stitch from the left needle to the right needle without working it.)

 
Working with 2 strands of black yarn together, cast on 28 sts Your second color (mine is blue) is also worked by holding two strands of yarn together.
 
Rows 1 & 2 - With Color A (Black) K
Row 3 - With Color B (Blue) *K2, sl2 with the yarn in back*, repeat from * to * to end of row.
Row 4 - With Color B (Blue) *Sl2, P2 with the yarn in front*, repeat from * to * to end of row.
Rows 5 & 6 - With Color A (Black) K
Row 7 - With Color B (Blue) *Sl2, K2 with the yarn in back*, repeat from * to * to end of row.
Row 8 - With Color B (Blue) *P2, sl2 with the yarn in front*, repeat from * to * to end of row.
Repeat Rows 1 - 8 for 6 more times to Row 56.
Row 57 - With Color A (Black) K
Row 58 - With Color A (Black) K2, (K2tog, K5) repeat 3 times, K2tog, K3 (24 sts)
Row 59 - With Color B (Blue) *K2, sl2 with the yarn in back*, repeat to end of row.
Row 60 - With Color B (Blue) *Sl2, P2 with the yarn in front*, repeat to end of row.
Row 61 - With Color A (Black) K2, (K2tog, K4) repeat 3 times, K2tog, K2 (20 sts)
Row 62 - With Color A (Black) K2, (K2tog, K3) repeat 3 times, K2tog, K1 (16 sts)

Cut yarn about 15 inches from Knitting needle. Put on a darning needle and remove the stitches from the knitting needle onto the tail end of yarn. Turn slipper inside out and pull yarn tight to close up end. Sew to secure. Continue to sew across top of slipper leaving enough room for foot opening (about 5 inches across the top). Sew up back of slipper.