[Harold Cavendish]

This is excellent, thank you very much for your help, Kalle!

I don’t really need the pattern but it’s nice to have because I was wondering how to do the mirror effect and maybe I’ll use it in some future work. For now, a combination of Offset Paths for simple and ‘compatible’ shapes coupled with your solution for the more ‘incompatible’ ones will be splendid. 🙂

[Harold Cavendish]

This is close to the solution: https://forums.adobe.com/message/6660522#6660522

Author: Rick Gerard

The only problem is that it only works for curves that start thick and end thin, not if you have thin ends and thick central part, which is what I need, unfortunately.

[Harold Cavendish]

I’m sorry but I don’t understand how to animate it to give the same effect. Let’s say I create a long horizontal line split horizontally in the middle by two masks (e.g. one set to subtract and the other as its inversion and also subtract). Then I can animate mask expansion to make the line continuously thicken but without the narrower tip. Could you be more specific about the animation part, please?

I need almost the same as the effect ‘Write-on’ with animated brush position and brush size, but the narrow line must expand with time to a certain point like this:

By the way, can this not be done with expressions? I’d like to just set the path and generate the line programatically.