These tips work with some adjustments in the rmPen.

According to a Facebook user:

I got them going: if you look at the head of the nib it's getting slightly thinner towards the “jaw” (to stay in the image…). After using a nail file and making it only slightly thinner it worked. Looks like it otherwise gets stuck after drawing the first line.

• feels like an ink pen
• slippery like writing on an iPad

It seems that you can also buy the Wacom ACK22201 black (hard) Tips and the Wacom ACK22203 white felt Tips in a 3+3 combi pack as ACK21616.