Smooth inner corner on a gradient stroke?

Question

I've decided I do not like that my plotter prints a white, hard-edge margin when I print a map even though there isn't one in my layout or PDF. I've decided to try doing a rectangle with a transparent to gradient  stroke around the whole layout with a 1/8th inch margin. So far things are great except that I want the corners to have a mitered "outside" and a rounded "inside."

Even using rounding it rounds the outside, but still miters the inside.

(Here's a white to white "gradient" stroke so it's more clear what I mean. )

I want a nice smooth curve in the corners of the layout.

@JohnMNelson  Any words of wisdom?

AlfredBaldenweck · Accepted Answer

Unfortunately I don't think you can do anything to prevent the plotter from adding those margins, and I'm not positive there's a real way to get what you want. Best I can do is to use a gradient stroke instead of a gradient fill.

I got a nice effect with a 30 pt stroke and a -15 offset.

Unfortunately, pushing it beyond 30/-15 got that miter effect you're trying to avoid.

Here's 40/-20

Check out a related Idea Add "Continuous" to Buffer Gradients (Symbology) - Esri Community

I'd also support an Idea for making the buffer maintain the outer shape all the way down.