Accurate Arch Templates in 5 minutes or Less

Many arched mouldings require a tracing of the opening in order to be accurately constructed. These instructions will allow you to create a tracing that we can use as a template to make your moulding.

1. Start with a clean sheet of paper large enough to cover the entire opening (window, doorway etc.). The best paper to use is lightweight brown kraft or white packaging paper, or even heavy gift wrapping paper. If these are not available, then you can use products such as Tyvek house wrap or red rosin building paper. Felt (tar) paper is strongly discouraged. The lighter weight the paper, the easier it will be to make an accurate template. A moulding that fits the opening properly depends upon an accurate template.

2. Stretch the paper across the opening and staple or tack it every 12″ or so close to the edge of the opening. Try to avoid using tape as this tends to allow the paper to shift during the templating process. Make sure the paper is flat across the opening.

3. With a small solid object, such as a block of wood, press along the inside edge of the jamb, making an impression in the paper. Do this all the way along the jamb opening. The small object should be held at a slight angle so that the lower edge is gently pressing into the opening behind the paper, bending the paper around the inside edge of the jamb. The lighter weight the paper, the easier it is to accomplish a clean and visible line. If there is a horizontal bottom edge of the opening, such as a window sill, turn the corner and continue the line a couple of inches in from either side so as to identify the bottom of the opening.

4. THIS NEXT STEP IS IMPORTANT. Take a lumber crayon (or a child’s crayon if one is not available), turn it sideways, and carefully go over the impression on the paper. Do this while the paper is STILL IN PLACE OVER THE OPENING. Run the crayon over the jamb edge just as you did the small block of wood. Keep this line as thin and clean as possible; if it becomes more than 1/16″ wide, use a pencil or pen to draw arrows showing the actual location of the jamb edge impression. Also write a note, such as “follow this line” by each arrow indicating that it points to the jamb edge impression.

5. Write all pertinent information on the template, including:

A. Indicate what the line traced; this will usually be the inside edge of the jamb. If it is the outside edge of the jamb, then also indicate the jamb thickness. A large arrow pointing at the line with a note saying “THIS LINE IS………” works just fine.
B. Tell us to make the casing just inside or outside the line (usually ž” to the outside if you traced the inside edge of the jamb) to allow for a proper reveal.
C. Write the Job Name (or order number), Opening Location, Moulding Profile and Wood Species on the template.
D. If the tracing is of an elliptical (or other non-true radius) opening, indicate which side of the casing is to face the line on the paper. This will usually be the back of the casing, but in some cases could be the front.


  1. Do not use tar paper.
  2. Do not submit folded up cardboard.
  3. Do not submit narrow strips of paper either in a single piece or in multiple pieces taped together.