The Man-Cub needed a cap and gown for his graduation ceremony. We had a leftover Confirmation gown (we actually had about 30 - so we donated them all to the school - they can keep them and use them for their graduation ceremonies for years to come) - but we needed a cap (Confirmation gowns don't come with caps). So of course I had to make one as like a 'real mortarboard' as possible - nothing made of crepe paper and poster board would do for this momentous occasion...
You will need a 9 inch square of cardboard and a little over a quarter of a yard of material in your choice of color - ours was red and shiny - which unfortunately doesn't photograph all that well.
Here's a pattern of what we'll be doing -

First fold your material in half and lay your cardboard on it - with one edge of the cardboard aligned exactly with the fold - then cut around the cardboard, leaving a 1/2 inch seam allowance.

Next - measure around your child's head - divide this number in half - then add 1 inch - enlarge this pattern (a rough sketch should do) to that length. The Man-Cub's head measures 21 inches - half is 10.5 - add one inch for seam allowance (1/2 inch on each side - so his cap was cut at 11.5 inches. Cut 2 pieces. Place right sides together and sew the end seams and hem around the bottom.

This is really the only tricky part - center the cap on one half of the rectangle - right sides together and pin in place - making sure that the rectangle remains flat.

Stitch this in place - you'll need to form a few gathers in the cap as you sew - I just pleated the cap material to make it fit as I went around the circle - but a perfectionist might gather it beforehand and pin it to the circle.

Next sew a button in the center of the other half of the rectangle.

I used a little scrap of cloth on the underside to give it a little more stability.

Finally - fold the rectangle - right sides together with the cap and button on the inside - sew the side seams - insert your piece of hard cardboard - it should be snug.

Turn under the seam allowance and seam this end with the zipper foot - so that you can get as close to the cardboard as possible.

Make a tassle of a contrasting color - we used black - but white and gold are also pretty traditional - I just cut about 10 - 1 foot lengths of shiny stash yarn - folded them over and tied them tightly just about 1 inch from the fold to form a loop - then slide another piece of yarn through the loop and make a knot and slip this over the button.

The Man-Cub loved his mortarboard cap! It was perfect for tossing into the air at the end of the ceremony.