Question: I've seen the following bookcases while I was on holiday, and I'd like to make something similar myself. However, I'm puzzled about the structure of the bookcase.

[![enter image description here](https://i.stack.imgur.com/5AcGq.jpg)](https://i.stack.imgur.com/5AcGq.jpg)
[![enter image description here](https://i.stack.imgur.com/7Aa4W.jpg)](https://i.stack.imgur.com/7Aa4W.jpg)

It looks like the vertical side walls are not made out of a single board (as "normally" happens in a bookcase), but are multiple individual pieces, and the shelves are fixed on the top/bottom of the side boards rather than on internal face.

[![enter image description here](https://i.stack.imgur.com/V03I0.jpg)](https://i.stack.imgur.com/V03I0.jpg)

I really like the look of it, but I don't understand how the vertical bits can be fixed safely to the horizontal shelves. Do you reckon there are some metal brackets in the back to keep everything square and to give some structural stability?
How would you fix the shelves to the side boards?

Answer: 
The verticals are probably set to the horizontals by dowels that run through all 3 pieces. Might be metal dowels - they make steel dowels with a spiral V-groove that helps it hold onto glue. Seems like they might have other uses too :)

[![enter image description here](https://i.stack.imgur.com/ENqYl.png)](https://i.stack.imgur.com/ENqYl.png)

The above would provide more than enough strength, but more than that, we tend to ignore **the backboard** as a structural member, because in flat-pack furniture like Ikea, the backboard is *weak tea*. But it does not have to be - it could tie the whole bookshelf together. The structural elements wouldn't even need to be full width, a few inches in from the edges would suffice. For instance someone could back the entire bookshelf with 1/8" lauan plywood *and behind that* install 1x4's on the outer edges. Use deck screws to tie those *through the lauan* into the verticals and horizontals.
I would use a stopped dado joint to allow the side panels to be mostly intact, but to have that exposed shelf edge on the front that you're interested in.

If it were constructed like that, it might be only the first inch of the shelf that you're seeing.

<https://www.table-saw-guide.com/dado-joint.html>
<https://canadianwoodworking.com/techniques_and_tips/stopped-dado-joint/>