I covered it with pearlescent wrapping paper and it took just two days to complete from drawing to finish.
CLICK! to watch the time-laspe movie
Step 1: Sketch Design
After deciding on the design, I traced it out on baking paper, drew the rest of the shape freehand, fitting into the small piece of cardboard I had found and cut it out.
This design is suitable for smaller pieces of cardboard. The two halves can then be put together if you cannot find a larger piece of cardboard.
I cut out the centre for an uneven shelf level to add a bit of dynamic to the final appearance.
Cut three frames for shelf support and one silhouette backing. Only cut struts for two inside frames. They are cut half-way.
Step 2: Trace and Cut Silhouette & Struts
The height of the strut will be equal to the height of each shelf level.
The struts are cut half way between the inner supports and the strut. The part I enjoy most is fitting the struts in each layer like a 3d jigsaw puzzle.
Step 3: Join the Pieces
I used a bit of quick sticking, polyurethane craft glue to join the struts at the front layer and back layer and edges. This seemed to work faster than using the electric glue gun. While I worked out side in the sun, everything dried pretty quickly.
Now wet the watercolour paper tape on the sticky side, trim slits for curves, press edges firmly together and paste on tape to strengthen your inner struts.
Step 4: Decorate
I brushed this glue mix onto the cardboard bookshelf when it had cooled. After putting out in the sun, it dried rock hard.
Working out the general amount of wrapping paper to use
First I placed the wrapping paper over a section here and there. I pressed the sides to form a crease all around each shelf layer. Then I trimmed around this pressed template with a 2.5cm border all around.
In the meantime watch Jenny Bertrand's demonstration for a quick overview with your cardboard furniture design. All you need to know to make your own designs arehere.
Also Camille has a detailed site about cardboard furniture design for beginners and is a great introduction into the cardboard design world. Especially helpful are ways for a more professional finish.
Step 5: Waterproofing - Another Way to Finish
The cardboard tended to sink once I'd painted it with the rice flour glue paste and the paper crumbled.
I did a bit of search and found Veronica's detailed site (in French) about how to give a professional flat finish to the surface of your cardboard designs.
I used the DIY joint compound recipe - the ingredients include calcium carbonate (cement mix), water, pva wood glue, preservative (such as vinegar / tea tree oil.)
Add (1:2) 1 part water to 2 parts calcium carbonate cement powder. Stir in 1 Tbl pva wood glue.
Store unused joint compound in a sealed container and it will remain workable indefinitely.
I painted this mixture onto the cupboard, dried it then repainted the top surface with the DIY joint compound mix. It dried to a hard, rocky surface.
If I was more careful, I'd paste it on with a spatula then filed it down smooth, and used wet n'dry sandpaper till it was flat.
However, in the picture below, I kept all the lumps and bumps and think it adds a bit of character to the final cupboard. Next time though, I might blend it thoroughly for a flat, chalkboard look.