Author writes:

This slipover uses another typically Finnish pattern, taken from a mitten knitted around 1930. The pattern, however, is considerably older than that, and is still popular today. The mitten combines a number of different elements, including free-flowing waves and three-leaf clovers, knitted in solid shades on a neutral background. Baltic uses only the wave-like patterns, in similarly strong colours.

(Pattern depicted in MC pale yellow, with red and green colourwork).