Voluminous Cardigan with Fantasy Stitch Pattern

How to work the voluminous cardigan with a fantasy stitch pattern:
One size
Materials:
800 g yarn (70 percent cotton, 30 percent Merino Extrafine wool, yardage 105 m per 50 g); Knitting needles 6.5 mm (US size 10.5, UK size 3).

Stockinette stitch: knit right-side rows, purl wrong-side rows.
Reverse stockinette stitch: purl right-side rows, knit wrong-side rows.
Garter stitch: Work all right-side and wrong-side rows with knit stitches.
Fantasy stitch pattern:
Row 1, Row 2 and all even-numbered rows: Work all stitches as knit stitches.
Row 3: 1 knit stitch, * 1 knit stitch, insert the needle into the stitch of the previous row and work 1 knit stitch, repeat from * throughout.
Row 5: 2 knit stitches, * 1 knit stitch, insert the needle into the stitch of the previous row and work 1 knit stitch, repeat from * throughout.
Repeat Rows 3 to 6 throughout.

Gauge:
Combination of garter stitch and fantasy stitch pattern using 6.5 mm needles: 14.5 stitches and 25 rows = 10 x 10 cm (4 x 4 inches).

Back:
Cast on 102 stitches and work 2 rows in garter stitch.
Continue with the following stitch distribution:
20 stitches garter stitch, 62 stitches fantasy stitch pattern, 20 stitches garter stitch.
At a total height of 64 cm, shape the shoulder slopes by binding off at the beginning of each row on both sides 13 times 3 stitches.
For the neckline, at a height of 11 cm from the beginning of the shoulder slopes, bind off the remaining 24 stitches.
Right front:
Cast on 66 stitches and work 2 rows in garter stitch.
Continue with the following stitch distribution: 3 stitches reverse stockinette stitch, 15 stitches garter stitch, 28 stitches fantasy stitch pattern, 20 stitches garter stitch.
Neckline shaping:
At a total height of 44 cm, on every right-side row at the right edge, after the first 17 stitches, increase 1 stitch in the last stitch of the garter stitch section, 16 times in total.
Work the increased stitches in garter stitch.
At the same time, on every fourth row at the beginning of the fantasy stitch pattern, decrease 1 stitch 8 times.
You will have:
3 stitches reverse stockinette stitch, 31 stitches garter stitch, 20 stitches fantasy stitch pattern, 20 stitches garter stitch = 74 stitches.
Shoulders:
At a height of 20 cm from the beginning of the neckline, bind off at the left edge at the beginning of each wrong-side row 13 times 3 stitches.
At a height of 22 cm from the beginning of the neckline, bind off at the right edge at the beginning of the right-side row once 35 stitches.

Left front: Work in reverse to the right front.

Sleeve:
Cast on 40 stitches and work 2 rows in garter stitch.
Continue with the following stitch distribution:
9 stitches garter stitch, 22 stitches fantasy stitch pattern, 9 stitches garter stitch.
At a total height of 10 cm, increase on both sides after the first stitch and before the last stitch on every eighth row 7 times 1 stitch.
You will have 54 stitches.
At a total height of 49 cm, shape the sleeve cap by decreasing on both sides after the first 3 stitches and before the last 3 stitches:
On every second row decrease 1 stitch twice,
On every fourth row decrease 1 stitch three times.
At a height of 6 cm from the beginning of the sleeve cap, bind off the remaining 44 stitches.
Work the second sleeve in the same way.

Finishing:
Work all seams using mattress stitch.
Join the shoulder seams.
For the collar, pick up stitches evenly along the neckline of the back.
If necessary, increase or decrease stitches to obtain a total of 62 stitches.
Work in garter stitch, increasing on both sides after the first 3 stitches and before the last 3 stitches on every fourth row 12 times 1 stitch.
At a total height of 8 cm, evenly increase 8 stitches on a right-side row.
At a total height of 16 cm, evenly increase another 8 stitches on a right-side row.
You will have 102 stitches.
At a total height of 19 cm, bind off all stitches.
Sew the edges of the collar to the front neckline edges with the seam visible on the outside.
Fold the sleeves in half lengthwise and secure the center to the shoulder seam.
Set in the sleeves over a height of 20 cm from the shoulder seam on both the front and back.
Work the side seams and sleeve seams in one continuous seam.