Jahit kain stiffener ke pinggiran topi secara melingkar. Satukan bagian pinggir potongan kain. Lipat pinggiran yang tampak kasar, lalu setrika sampai rapi. Jahit kain stiffener ke pinggiran kain. Buatlah kerutan disekitar lingkaran topi. Satukan bagian atas topi dengan jarum. Jahit bagian atas topi di pinggir untuk menyatukan keduanya. Selesai.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Take the stiffener or interfacing and fold it in half lengthwise, to make the strip half as long. Then use a sewing machine or sew by hand to create a seam about ¼ inch (.63 cm) in from the edge that connects the shorter, raw edges of the interfacing. Do the same for the brim piece, so that you are left with two loops. Take the loop you made from your brim piece and cuff it in on itself to make it half its original width. This should leave you with a cuffed piece of cloth that has a folded edge