trying to mat a 16x20 print in a 4" wide - 28x36 oval frame fora 20 ft gable window

[paw92]

I have a 28x36 oval frame that is 4" wide and a 16x20 rectangular print. Background mat will be oval. question is can I do a 1" darker mat in a rectangle around the 16x20 print?? Tried to share an attachment of what I have but don't know how on this site. Pat

 

[KmH]

How oval is oval?
An oval is an ellipse. Ellipses are defined by their eccentricity.