As the title implies, the ultrasonic welder is a super accessible, easy to use machine. With brief planning, a small project like this can be finished in under half an hour. The pen case in this post was made by our new volunteer, Alex Newby, with a special pocket for her pen nibs and space for her ink container.
You can see the darker blue lines where the seam was "melted" into the material.
Trimming the edges makes the project look clean. Since the seam is the same throughout the whole width, you could trim some of it away if you want a smaller more discreet seam.
2 minutes work, and you have the start of an abstract piece: