We have explained this in our latest
instructions:
Rolling in a star pattern is not recommended any more.We, like every other dermaroller vendor, used to advise to roll in a star pattern. However, we
determined that that is not the optimal technique because if you roll in a star pattern, the center of
the pattern gets a much greater prick density than the perifery. A perfectly uniform prick density
can only be achieved when you roll at straight angles, such as only horizontally, or only vertically,
or both.
Rolling back-and-forth without lifting the roller is not recommended anymore.We discovered that the way nearly everybody rolls is responsible for the infamous "scratches"
effect, caused by an extreme prick density distributed over narrow "bands", as shown on page 11. If
you do not lift the roller after each rolling movement but keep the roller head's needles inside the
skin, then the roller will resist sideways movements because there are always needles in the skin,
producing a "railway" effect of a train on a track. Then when you move a few times back & forth,
you'll hit the same pricks again and again, causing a locally too high prick density or larger-diameter
pricks in the skin. Both are undesirable effects.
The only correct way to roll, achieving a perfectly distributed prick density is to roll horizontally, and
after every roll, lift the roller and position it a few millimeters from the previous starting point,
repeating the rolling movement and so on, until the entire skin area has been treated. If you want
to increase the prick density, repeat this process under a ninety degree angle as shown on the next
page.