There are four main factors affecting the choice of tattoo needles cartridges: their diameter and taper, with their configuration and numerical count. The needle's diameter is its physical width, with the most common choices being #8, #10 and #12 needles. Of these, #12 is the largest and most common, whilst most people use #10 needles for their line work. The taper shape can be longer or shorter depending on the manufacturer and personal preferences, but is generally around 2mm. Each artist has their own preferred needle diameter and taper length and we try and make sure we sell the most popular arrangements. The configuration and count of needles refers to the shape the needle makes. The count determines how many points are on the end of the needle? Most common being 3, 5, 7 or 9. As to their configuration, there are different otions: the round liner (RL), the round shader (RS), and magnums in weaved arrangements (M1), or round magnums (RM).