Making an Impossible Bookshelf

One of my hobbies is making unusual furniture. The largest piece I've made is this Dr-Seuss-inspired playroom cupboard below.

Our playroom cupboard, which has a two dens built into it, one in each of the top corners.
The left-hand den is accessed via a ladder and trapdoor behind the left-hand doors.

As you can see, one of the cupboard's less playful functions is as a bookcase. The problem is, like most book-lovers, it didn't take long before it was full to overflowing and we needed somewhere else to put the surplus books.

The only wall-space that was free in playroom was above the arched doorway next to the cupboard. I thought about extending the cupboard over the arch, but decided I couldn't do that without the extension looking like an ugly bolt-on, so I played around with a few other ideas. 

I liked the idea of doing a bookshelf that followed the archway below it, so I googled a few photos of arches for inspiration. I've alway been impressed by the simple elegance of self-supporting stone arches like the one shown below and they provided the inspiration I was looking for.

I decided to make a bookshelf in which books fanned out like the voussoirs (the wedge-shaped stones) that make up a stone arch. Here's what I came up with.

There were a couple of problems that had to be overcome. Books are not wedge-shaped, so they will not fan out neatly into an arch like voussoirs do without some help. And I needed to find a way to stop all the books in the middle of the shelf from sliding down to the sides if someone took a book out from one of the ends.

I realised I could solve both problems by fixing angled bookends at regular intervals along the shelf. However, rather than spoil the impression that the arch was entirely made from books, I disguised the bookends to look like dummy books.

The real books are held in an arch-like fan by dummy books that are part of the shelf.

Rather than use real book and author names for the dummy books, I decided to have some fun and came up with a list of book titles with punning author names like Art is Rubbish by Phyllis Stein (Phyllis Stein - philistine - geddit!).

The dummy books all have punning author names.

Most of the dummy books would be sandwiched between real books, so I only designed the spines. However the front and back of the two on either end of the shelf, which appear to hang off at impossible angles, are visible, so I designed whole covers for these.

I designed whole cover for the two dummy books at either end of the shelf.

I even wrote some blurb for the back covers!

In case you want to have a go at making your own impossible bookshelf, here's a quick run through of how I made it.

I measured the existing arch to work out the radius I would need. Then I made a card template for the backboard of the bookcase,and stuck this to the wall with Blu-tack to check that it looked right on the wall.

I used the template to mark out a cutting outline on a piece of 12mm thick MDF board and cut out the outline with a jigsaw. Then I drilled in 5 holes (to allow the shelf to be screwed to the wall) and routed in a series of grooves into which the other pieces of the bookshelf would be slotted: ten short straight grooves for the dummy books and one long curved groove for the shelf piece.

WARNING: If you are cutting, drilling, routing or sanding MDF,  you should wear a face mask to avoid breathing in the sawdust.

The drilled and routed MDF backboard

The shelf-piece is made from two layers of 6mm thick flexible MDF. This is ribbed on one side to allow you to bend it. I cut a couple of pieces to the right size (I could not get a single piece long enough) and then glued these, with the smooth side upwards, into the long curved slot using PVA wood glue. 

Flexible MDF is ribbed on one side to allow it bend.

I cut some 9mm thick MDF into rectangles to make the dummy books and then glued these into the other slots and to the shelf piece. I also hammered some panel pins through the underside of the shelf-piece into the base of the dummy books to make them extra secure.

The base board with the dummy books and shelf-piece in place.

One layer of flexible MDF is not stiff enough to use on its own, so I cut a second layer and used some PVA glue, applied with a small paint roller, to sandwich it to the bottom of the first layer. The smooth side needs to faces downwards on this second layer, so that you have a smooth face on the bottom of the shelf. The two layers need to be held firmly in place while the PVA dries and I had to use every clamp I had to do this.

A second layer of flexible MDF is glued to the underside of the first.

Once the PVA had dried, I used some wood filler to fill in the ribbing holes in the edge of the flexible MDF and sanded the whole thing down ready for painting.

I used wood filler to fill in the holes in the edge of the flexible MDF.

I painted the shelf with a water-based satinwood paint and a spray gun, but you could use an ordinary paintbrush. Once the paint had dried thoroughly, I printed the dummy covers onto card and covered them with some book film (clear sticky back plastic) before sticking them onto the dummy-book pieces on the shelf.

The dummy covers were stuck to the shelf using a strong, solvent based
glue and held in place with bulldog clips and clamps while the glue dried. 

And that's it!

… However I have an admission to make.

The bookshelf shown at the top of the page is actually the second one I made. The first one is shown below. The difference between the two is that the first one has a slightly smaller radius that is tight up to edge of the door arch. It looked great when I fixed it to the wall and I was really happy with it – until I opened one of the doors and found that I could not open it all the way because the top of the curved door was banging on the bottom of the protruding shelf. I had some colourful words to say about this discovery.

The Impossible Bookshelf Mark 1 looked great,
but stopped the door beneath it from opening fully.

I could have simply moved the shelf a few centimetres up the wall, but then it would no longer match the curve of the arch and I knew that this would grate every time I looked at it. And we could have put the shelf up in the kitchen on the other side of the archway (where the doors would open away from the shelf), but there was not enough space on the wall on that side.

So I ended up putting it above my office window, where it just fits snuggly.

My first attempt has been put to good use in my office.

And then, I started all over again and made another one, with a slightly bigger radius, so that it wouldn't catch on the top of the door.

If at first you don't succeed …

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Update: March 2022

Since writing this post I've been contacted by three people who have made their own impossible bookshelf, including Paul Roodenburg, who contacted me via the comments section and made the shelf shown below. Instead of creating fake covers for his dummy books, Paul used the real covers taken from secondhand books, which is a clever alternative.