When we moved into our loft we decided that a Pax wardrobe from Ikea would be a perfect way to divide the living room and bedroom. The problem is that Ikea doesn't intend for Pax to be a room divider, it's meant to go against a wall, so the back was unfinished. In the short term when I assembled the units I turned the flimsy cardboard like veneer that's intended to finish the back inside of the wardrobe (with the same colour as the outside) around so that the back of the wardrobe (on the living room side) was the same colour as the rest of the wardrobe. Inspired by the Hobbit wall we decided to finished the backside of the wardrobe by decoupaging sheet music. We choose sheet music as it's a large part of both of our lives but it could have been a dictionary, novel, poetry, newspaper, maps, or anything else on paper.

What you'll need.
Some sort of boards to create a solid backing for the decoupage application.
Screws to attach the board
Primer (we used Kilz as it's inexpensive and does a great job)
The paper, whatever you choose to use.
White glue (we bought lapage in the four litre bottle for $15)
Foam brushes (get lots of them, they're cheap and they'll break if you're doing the 200+ sheets like we did)
'''Polycrylic'''
Trim (metal, wood, whatever you want)
Adhesive (to attach the trim: we used liquid nails)

Step 1: Strengthen and Prep the Surface

The boards cost a meagre $8 each from home depot. It's a inexpensive fiberboard that'll be covered anyhow and it functions to provide rigidity and a smooth surface for the decoupage. We were covering three meters in total. We have four units though, to at 50cm and two at 100cm. We had the folks at home depot to cut the boards (and they didn't charge us for the cuts). We needed three boards in total.

We pre-drilled the holes about every 6-8 inches. You can't just screw it in as it'll crush the board. Take the time and pre-drill.

We screwed the boards in and we're relieved to find that they were cut perfectly and fit as they should.

We mounted all the boards and than vacuumed and wiped it down in preparation for the primer.

We primed it with Kilz primer. The only thing we should have done is taped the joins with masking tape first and then painted. Then the wall would have been seamless. The wet paper likes to get into the smallest crack and bubble.

Step 2: Get Your Paper Ready

While you're wainting for the primer to dry you may as well be productive.

Whatever you've choose to use get it ready in advance. It'll save you headache in the end. Pay attention to things that'll stick out like bar codes. We used sheet music, original compositions, a few scores, jazz charts, photocopied a few pieces that meant something to us (and we didn't want to destroy the original) and tried to represent a range of music genres.

Step 3: Start the Decoupaging

With many projects the prep work is the most work. With this project the decoupaging is time consuming so get ready to put in some hours. We were picky with order and viability (things we likes and wanted to display being prominent). In total I think it took around 8 hours to decoupage the wall. Keep in mind that's about 90 square feet worth of wall.

To decoupage mix the white glue (in a container) with some water. We found that 1 part water to 4 parts glue worked the best. Not too watery but not too thick.

Lay out some wax paper to work on. It works nicely to reduce the mess. Replace the wax paper every time it gets to tacky and messy.

Take a piece of paper and using the foam brush paint the back side of the paper with the glue mixture (on the wax paper). Paint a patch roughly the same size as your paper on the wall.

Put the paper on the wall where you've just painted and apply more glue the surface of the paper working from one corner and trying to get rid of as many bubbles as possible. Repeat. Repeat. Repeat. Etc.

Note: once the glue dries the paper will tighten up and many of the small air bubbles will disappear.

Keep going. Overlap as much as you want to. We decided to keep everything level but you could certainly turn the paper in different orientations as well.

Step 4: Seal It.

Once the walls completely dried (wait a day) apply the sealer. Polycrylic is water based but it'll still make you light headed. Make sure you have ample ventilation. I used a foam brush (as I didn't want to do a lot of clean up) and it took me about 1/2 hour for each of the two coats (two hours apart).

Step 5: Add Trim and Smile.

We were able to find trim at Home Depot that matched the brushed aluminum texture of the Pax doors that we have. I think each 8' piece was about $15. I found it funny that the two pieces of trim cost more than all the boards. We used the hacksaw in Home Depot to cut it to size. We used liquid nails to glue them on either side. For the baseboard we had some left over from the original construction that was conveniently already painted to match the rest of the baseboards. I cut it to size, mitered the edges and glued it in place.

And that's that. All done.