Here's an image that is extremely clean
Here's a detail from it
Here's a typical not-so-neat one
and here's a detail from it
Here's a flea plowing through an abutting line in the image above. I started it just to the left of the abutting line so it would be seriously affected by it. The flea expanded a lot as it went through the abutting region, then slimmed down as shown.
