Here’s another pen that I’ve been enjoying with both Spirograph and Wild Gears: PaperMate’s InkJoy.
They come in different qualities from the 100 series to the 700 series, with the difference more in the shape and quality of the barrel. The ink is the same, as is the ink delivery mechanism, according to the comparison chart on the Amazon page (scroll down to see).
I have the 100RT, 1.0M – the “everyday” quality, meaning cheap, and they do feel rather cheap, but the ink flows smoothly. It makes a finer line than the felt tip pens I’ve been using.
My only criticism of them is that occasionally I get a smear when the wheel passes over a clump of ink that hasn’t dried yet. Smearing is more of a problem on high-gloss paper than on regular, more absorbent paper.
These pens are very inexpensive, so it’s worth giving them a try.