Abbreviations:

K, k	Knit
P, p	Purl
st, sts	Stitch, stitches
dpn(s)	Double-pointed needle(s)
CO	Cast on
K2tog	Knit 2 together (a 1-stitch decrease)
P2tog, p2tog	Purl 2 together (a 1-stitch decrease)
SSK, ssk	"Slip, slip, knit": Insert right needle into the next st as if to knit, but slip it from the left needle to the right needle without knitting it ("Sl 1 knitwise"); Sl 1 knitwise (that is, repeat the first operation); insert point of left needle into the two slipped sts, in front of the right needle, and wrap the right needle to knit them together from this position (a 1-stitch decrease).
*...*	Repeat the instructions between the asterisks for the rest of the round, unless otherwise directed.
Rem	Remaining

CO 60 sts in color 1. Distribute on 4 dpns: Needles 1 and 2 are instep sts, needles 2 and 3 are heel sts.

Rounds 1-9: *K2, P2*.

Round 10: Increase to 72 stitches spaced evenly (i.e., 3 sts per needle).

Begin patterns:

Note: In all charts, work unmarked squares in color 1, marked squares in color 2.

Rounds 11-35: Join color 2. Following chart 1, repeat chart 3 times around.

Rounds 36-38: Following chart 2 repeat chart 12 times around

Round 39: In color 1, knit to last 2 sts of needle 2, ssk (35 sts on instep needles).

Heel flap:

Arrange all heel sts (from needles 3 and 4) onto one needle (36 sts on heel needle).

Rows 1-20: Following chart 3, knit back and forth until heel flap measures 2.25 inches (5 vertical repeats of chart).

Turn Heel:

Work heel turn in color 2.

Row 1: Sl 1, k19 (4 sts past the middle of the heel), ssk, k1, turn.

Row 2: Sl 1, p8 (4 sts past the middle of the heel), p2tog, p1, turn.

Row 3: Sl 1, knit to 1 st before the gap made by turning, ssk, k1, turn.

Row 4: Sl 1, purl to 1 st before the gap made by turning, p2tog, p1, turn.

Rows 5-14: Repeat Rows 3 and 4 five times more (24 sts).

Row 15: K12; with a new needle, K to last st, k1 in row below last st, k1 (12 sts on first heel needle, 13 sts on second heel needle.).

Gusset:

Round 1: With a spare needle, pick up 16 sts on left side of heel flap in the following stripe color pattern:

Stripe pattern: *K3 in color 1, K1 in color 2*.

If you wish to pick up a corner st, it must be one of the 16 sts picked up or it must be decreased immediately; to maintain and properly center the Stripe pattern, sts must be picked up in a perfect multiple of 4.

Continuing with the spare needle, K2 of the instep sts from needle 1, at the beginning of a stripe pattern repeat; place marker. Continue in stripe pattern to end of needle 1 (34 sts).

Work needle 2 maintaining stripe pattern as established, to the last 2 sts of needle 2; place marker; work rem 2 sts of needle 2 as k1 in color 1, k1 in color 2.

Continuing with needle 2, pick up 16 stitches on right side of heel flap following stripe color pattern:

Continue stripe pattern across needles 3 and 4 heel stitches. (92 stitches total).

Rearrange sts: Slip the last 6 sts of needle 2 to needle 3.

Round 2: Work the first 6 sts the beginning of needle 1 onto the end of needle 4; Following stripe pattern, knit decrease rounds:

*Needle 1: K to 2 sts before marker, k2tog, knit to end.

Needle 2: K to marker, slip marker, ssk, knit to end.

Needle 3: Knit to last 3 stitches, k2 tog, k1

Needle 4: Knit.

Round 3: Knit in stripe pattern.

Rounds 4-25: Repeat from * 11 times more, until 17 stripes (68 stitches) remain on needles. Gusset complete.

Foot:

Round 1: Knit 4 sts from needle 1 onto the end of needle 4. Now rearrange the sts so that the next 25 sts to be worked are all on needle 1, with the remaining 48 sts divided among needles 2, 3 and 4 (16 sts each).

Rounds 2-26: Follow chart 4 on needle 1; continue stripe pattern on the other three needles. Continue as established for the remaining 24 rounds of chart 4.

Remaining Rounds of Foot:

Rearrange sts so there are 17 sts on each of 4 needles, with the instep motif of chart 4 centered over needles 1 and 2.

Check the length of the sock. The toe will take 18 rounds, plus one grafting row. Slip a marker in a stitch. Count 18 rounds up or down that column of sts; slip a marker in the next st in the column. Measure between the markers; that will be the length of your toe. Before beginning the toe, the sock, folded flat in profile and measured from the fold at the center back of the heel, must be the total desired length of your foot less the length of your toe. If sock is not long enough, continue stripe pattern until sock is long enough to begin the toe.

Toe:

Rounds 1-18: Starting on instep needle, Follow chart 5 for toe decreases. One full repeat of the chart spans both needles 1 and 2; another full repeat spans needles 3 and 4.

Graft toe closed.