I'm new to Affinity Designer and I'm going to be using it to make diagrams of biological pathways and to annotate data. I've stumbled into a problem when creating curved arrows. I can convert the arrow shape to curves, but it becomes very difficult to maintain the shape and thickness of the arrow. If you look below the curved arrow still doesn't necessarily have the same thickness throughout even after optimising it.
While I am at it, I would also like to create a circular arrow that gets thicker as I go around. I've also attached an example (circular arrow, although it doesn't get thicker as it goes around).
Any help would be greatly appreciated!