Change the operation of these lines to score.
On a device, the path is Edit, Operation, then Score.
On a computer, change the operation from the menu at the top of the screen.
Once the line has been changed to score, those lines are now dashed.

Lastly, highlight those score lines and the box outline, and Attach.
The design is now ready to be cut. Click Make and choose the material. I am using the 65lb cardstock setting.
When cutting paper, increase the pressure to More, then follow the prompts as to when to load and begin the cut.
