Step 3: The ribbons and the holes
Now clamp the sections between 2 boards (I used very strong cardboard). Draw with a pencil and a ruler a line at about 0.5 to 1 cm from the edges depending on the size of your book. (I did 8 mm) Locate the middle and place your ribbons about halfway between the middle and the first line you drew.
Draw a line just next to the ribbon you're holding. You will later sew the ribbon into place at that location.
It doesn't matter very much where you place your ribbons. If it looks good, it probably is.
Normally for normal books there are quite precise places where to put your ribbons but I don't remember them and lost the piece of paper where they are on. But for a book this small it doesn't even apply.
Try to make it symmetrical! Because later while sewing I flipped some of the sections and they are a tiny bit out of place, but this doesn't matter.
Now get a knife and gently cut along the 6 markings you have applied. The ones at the side and the ones next to your ribbons. Make the cuts deep enough to penetrate all 3 sheets of paper.
This will create the holes trough which you will guide the string whilst sewing.
get the sections out of the clamp.