I just found these little mini books in a box.
Had to look close to think how they were made.
They were A6 in size.
That would be 10.5cm high by 7.5cm.
Easy to do.
Mine was C6.
Cut an envelope to make a pocket.
Either seal an envelope and
just cut 1mm of to open it,
or use a longer one and cut it in half.
Measure your pocket
10.5cm by 15cm.
and cut the pages to the same size.
Fold everything in half.
Now glue a page to the envelope front
and then fold so the page is inside.
Lay two of the folded envelopes next to each other
so the folds are touching.
Glue another sheet of paper to join both envelopes together.
You now have an envelope back showing,
3 double pages,
and another envelope back.
You just keep adding envelopes till you have enough double pages.
Cut one of the folded pages in half and glue one bit
to the front and one to the back.
To cover the spine I just glued a strip of paper over it, that was big enough to give me a 2cm overlap onto the front and back covers.
And added some page mats to each page.
what do you think?