I think this is a gorgeous jumper that uses knit and purl stitches to make these fantastic patterns. Bloody lovely AND it is sized from newborn to 7 years so you can make them for all of the family.
These patterns are knitted in King Cole Cherished DK, a super soft and smooth yarn designed with babies in mind. I would also recommend trying King Cole Majestic DK for this pattern for the older ones, it has dollop of wool in the fibre content and comes in some stellar colours that would really make the patterning pop.
These patterns are knitted on 3.25mm and 4mm straight needles.