Hi Simon, also one other thing,

> When a curve is formed from 'joined-up' edges in
> Sketchup the rendering seems fine.

Even without doing that, the stylized edges should show up when you zoom in on them a bit.

Do you see that happen?

Edges that are large enough on the screen at your current zoom level and view angle should show up already without doing any extra processing on them.

It just seems to be a limitation of the "sketchy styles" engine that it does not really like to have small edges, it would probably work better if they could automatically join together a series of small edges around a surface boundary if they find that they are too small to show up in the regular rendering.

- Michael