These hats I made at the beginning of my summer holidays. The inspiration I got in the technique we learned in our arts class in school for making yarn ornaments. For the small one it took me two days and for the big one, since I had to roll the thread to get the design I wanted, I needed 5 days.

Materials

1) Different colored yarns (2-3) , about 30m total length
2) Wallpaper glue (in powder, dilutes with water)
3) Wider painting brush
4) A pot to mix the glue in
5) Aluminum foil, less than 2m (The ticker the foil is the better, because it is going to peel off easier at the end.)
6) A bowl
7) A needle and a thread to sew parts of the hat together
8) Scissors
9) Some damp cloth or paper towels to wipe off the hands

Step 1: Mix the Glue

Put wallpaper glue powder and water in a pot, then mix a bit and leave it for two hours to make a compact mass. (In my case it was a local Serbian wallpaper glue brand, that is on the image). In the beginning there will be lumps in the mass. If there are still lumps after two hours, you should mix it until the mass is smooth.

Step 2: Prepare the Bowl (the Shape for the Crown of Your Hat)

Find a bowl that fits your head, than put aluminum foil around it. Make sure that the foil doesn't move from the bowl.

Step 3: Start Putting the Yarn

When you are done putting the foil around the bowl and your glue is ready you can start fixing the yarn over the foil. You have to spread some glue over each new piece of thread you put over the foil.

(A hint: do not put too much thread, the hat will be heavy for wearing, neither put too little, it could easily break.)

This will be the crown of your hat. Make the side parts of the crown as long as you wish. Make sure that you have common edge on all of the sides. You can do it by putting yarn two or more times around so that it makes a firm edge of the crown. Later on you will sew the brim to it.

Leave the yarn and the foil over the bowl until it firms.

Step 4: The Brim

To make the brim of the hat put the foil on a flat surface. Then adjust the hole in it to fit the circumference of the crown, leave additional centimeter inside. Think of how wide the brim should be and perhaps you would like to adjust the width of the foil.

Start putting yarn and gluing it down to the foil as you previously have done with the crown. At the end you might want to put some additional line of thread to both edges of the brim to get them hold the shape of the brim once the foil is removed.

Let it dry and firm.