Summer days and nights … with light and darkness.
On this summer shirt, front and back are worked the same way, with the only difference that the front’s main color is light and the back is dark … but you could also wear it the other way round, just as you like. The colorful small stripes (optionally arranged in a fade sequence) are the same for front and back: They are worked in the round, while the main color rows are worked back and forth, twisting yarns at the sidelines, with a Seed Stitch panel distracting the eye from the color transition.
The shirt is worked bottom-up and joined at the shoulder using the 3-needle-bindoff method.

Gauge: 28 sts x 40 rows in Stockinette.

Needles: Main needle size is 3,0mm: you will need 2 needles (double-pointed ones of at least 60cm) for this!
2,0mm needle for picking up sts, 2,5mm/ 2,75mm used for edges.

Yarn usage: Approx. 800/ 900/ 1000/ 1100/ 1200 m of a (Light) Fingering weight yarn needed, approx. 40% per main color (MC) and 20% for all stripe colors put together – only 11-15m per contrast color (CC) needed for a stripe of 3 rounds, and there are 18 of those thin stripes.

For my sample, I have used Sandnes Tynn Line (50% cotton, 33% Rayon, 14% linen, 220m/ 50g), combined with leftovers of a few similar yarns like Isager Bomulin for some of the thin stripes.

Sizes: S, M, L, XL, XXL (with bust circumference of 104/ 112/ 120/ 126/ 132 cm), hip width is a bit less.
The shirt should be worn with 5-10cm ease at bust.

Worked at a gauge of 2 sts less on 10cm, the shirt will become approx. one size bigger.

Errata:
Row 2 in table on page 5 should be:
Purl to 18/ 19/ 20/ 21/ 22 sts after neck marker, turn
(so that 27/ 29/ 31/ 33/ 35 center sts will remain unworked after finishing the other shoulder, too).
(concerns size S only).