The Clover White Marking Pen is like a rollerball, and produces a fine line, which goes white as it dries - you need to allow a few seconds for the line to show. The third photo shows the line just after drawing, while the fourth shows how it dries white. The fifth photo shows the Clover pen line at the top and the white Sewline Fabric Pencil at the bottom, for comparison. No need to press hard or scribble the line back and forth, just normal drawing pressure is all you need. This marker is particularly good on very soft fabrics, like Azumino cotton.

This pack includes the pen, plus a refill, and is available in the Japanese packaging only. When your pen runs out, don't throw it away - just replace the roller refill, and your pen is good to use again. A small metal gizmo to prise out the original refill is included (the illustration on the packet shows you how - it is the same as removing the refill from a Bic biro). Packet information is in Japanese, but it is very easy to follow the diagrams and insert the new refill. Saves money, and saves on plastic too!
 
The marks don't rub off easily like chalk lines can do and will stay on well even in warm, humid weather. The lines wash out and can also be removed with heat (such as by pressing).

Extra Refills are also available - Japanese packaging only.