The 21 needles are soldered with a rounded edge, allowing you to make wide and dense transitions between shades. Makes maximum saturation in shade transitions when overlapping colour on black shades.
Ideal needle spacing for applying large quantities of pigment in one pass. The special taper of the needle tip reduces trauma in the case of dense colouring.
The rounded edge allows you to create a soft transition between shades, giving a smoother effect to the image.