Fat Eighths are 22 cm x 55 cm  (9" x 22") - including selvages 

Fat Quarters are 50 cm x 55 cm (18" x 22") - including selvages 

Layer Cakes consist of 25 cm x 25 cm (10" by 10") pre-cut squares

Charm Packs consist of 12 cm x 12 cm (5" x 5") pre-cut squares

Jelly Rolls consist of strips 6.35 cm x WOF (width of fabric - which can vary between 104-115 cm (41-45"))

We recommend using a size 75 needle and 50 wt thread when sewing batiks because they have a tighter weave than your average quilting cotton.