This Stitch looks best using contrasting colours. It looks nice & it is so simple to do!
Multiple of 3
Abbreviations: C: colour; sl: slip; k:knit; rep: repeat
Row 1: C1: *sl 1 purlwise, k2*, rep from * to * until end
Row 2: C1: k
Row 3: C2: *k2, sl 1 purlwise* rep from * to * until end
Row 4: C2: k