Concertina Sketchbooks: Making Detachable Covers

The covers are done - hurrah! Making them isn't as tricky as you think, honest. You need:

Book board: warps less, but any thick board could be substituted I guess. 

PVA glue and a biggish brush (don't let it dry on the brush!).

Cloth: I've used regular cotton before, but book cloth is stiff and paper-backed, so easier.

Book vinyl: for the spine (though again you could try other materials).

Endpapers: any thickish, patterned paper works.

Medium weight card: a small piece to create a flap, to hold the folded paper in place.

You also need lots of scrap paper, to help create both a clean and a 'gluey' work area, side by side.

I started by cutting 2 pieces of book board: you need to allow 5mm more than your folded paper inner all round. I then cut 2 pieces of book cloth, allowing about 20mm overlap on three sides, but cutting it 20mm short on the spine edge. You stick the book cloth pieces to the boards (it's easier to apply the glue to the board, rather than the book cloth):

You turn it over and cut off the corners, snipping within 2mm of the board corners:

Then you glue all the excess cloth edges and stick them down, making sure to pull the cloth tight over the board edges (sorry, just realised this photo is up the other way - bit confusing, but you get the idea):

The corners are slightly tricky (this is where the book cloth really helps). You use your thumbnail to tuck the cloth into the corner on one side, then fold the other edge over to seal a neat corner:

Next comes the spine. I measured the width of my folded-up paper inner at 15mm. I didn't squeeze the paper too tight, so it wouldn't be under too much pressure and the book would close more easily. 

This is where the vinyl comes in: you need a piece to join the two boards together and create a strong spine. Book vinyl is great as it's very strong but also takes pencil on the reverse, so it's easy to measure and cut to size. 

I measured 35mm, to stick to each board, plus the 15mm spine, so 85mm wide. It needed to be as long as the board height, plus an extra 20mm top and bottom to fold over. I drew all this onto the vinyl, so it was easier to line things up when sticking on the boards: 

I put PVA glue onto the vinyl one half at a time, placing each board so it sat within my pencil lines, until it all looked like this:

Then I glued the excess vinyl top and bottom and folded it over, making sure it was pushed well into the spine. 

I then cut another strip of vinyl to go on the spine's inside. That needs to be just 1mm shorter than the book height, both top and bottom, and roughly the same 85mm width. When you glue that on, you need to really push it into the spine edges, so it's snug against the board and stuck tight to the other piece of vinyl:

There is a book-binder's tool which is designed for that job, but there are plenty of things which will do the trick, including a thumbnail.

Then you do the endpapers. You would normally stick the paper to both sides but, in this case, the inside back cover is going to be completely obscured by the flap we need to make, to slip the paper insert into. You just need to cover the front. Measure a piece that is 4 - 5mm smaller than the front cover all round and stick it on.

You're nearly there now. I'll tell you how to make the card insert next time, as this is turning into a very long post.