In InDesign it's a different process as noted below.
- Create your box as a solid color - in your case black
- With the box selected, go to the effects panel and from the 'fx' dropdown choose "Gradient Feather".
- Play with it until your hearts content.
Thank you, Rik! I had tried gradient feather, but it looks like I was mixing too many effects and that's where the muddy color was coming from.
I find this ridiculous - I use both Illustrator and Photoshop for years. Although even between them it is different I still could figure out how to do it there. But no chance on InDesign. Why, Adobe, doesn't it work exactly the same in all three apps???? C'mon!
I need a frame where the edges have a gradient to transparent, BUT the content may not have this vanishing / gradient effect.
So only the frame and not the content.
The content is already transparent around the image.
The frame does have to get an edge that becomes transparent on the top side, eventually with a gradient.
I now have done it with an image on top of a frame, or placed within.
But I do not get it to get an object stule where only the frame edge get affected and not the image that is copied in.