When rounding the edges of a rectangle band, distorsions from the flat horizontal (see attached image)
seem to be unavoidable - or is there a way to achieve rounded edges without this kind
of distorsion ?
Hi Tom, the main way to improve that is to make your object a solid rather than an open surface. You can do that by using the Construct > Planar command on your base shape before you did the fillet, that will put top and bottom end caps on it. With the end caps in place if you then fillet those edges the fillets will be extended past and trimmed by those end caps and give a result like this:
