And just to clarify on how you do the unwrap using curve flow, you have 3 pieces:



#1 is half of the top edge of the cylinder. This is the object that you will give as the object to deform, select it before running Flow.

#2 is half of the bottom circle of the cylinder. This is the base curve for the flow.

#3 is a line that has the same length as the half bottom circle, this is the target curve for flow.

Usually Flow is done with a straight line base curve onto a curved target but you can do it curved to straight as well.

This will be the result, it is floating above the line, you do the other halves in a second run of flow:



- Michael