Customizable, Modular Cardboard Storage Units: 3 Design Ideas!

My family has most of our groceries delivered these days, so we've accumulated many, many cardboard boxes over time. They come in three standard sizes: 12”x12”x6”, 12”x12”x12”, and 12”x12”x18”. I've kept most of these boxes in a good condition - they're still clean and sturdy. Instead of just recycling them with other paper waste, we wanted to make good use of them!

Building off our first cardboard furniture project (https://www.instructables.com/Portable-Flexible-Cardboard-Box-Furniture/), we decided to make furniture that could be used for storage instead of just a table or a chair. In this Instructables, we will teach you how to use the 12”x12”x12” boxes to make a wall display and infinity cube shelf, and used a variety of box shapes to make a Mondrian Squares-inspired wall display.

Supplies

Material

• Cardboard boxes. We used the smallest boxes for display sets and the medium boxes for storage, but you can apply the same technique to any box size and create your own pattern.
• Zip ties (optionally, use strong 10 mm jump rings)
• Tape
• Decorative paper, such as self-adhesive wallpaper, card stock, etc.
• Anything that can cover up the logos on the cardboard boxes will work, as long as you're satisfied with the results.
• Optional: short wooden plant stakes for support

Tools

• Scissors
• Awl
• Craft knife
• Hot glue gun

Step 1: Prepare the Box

First, remove the excess tape from the boxes and make sure the boxes are clean. You can paint the boxes right now, but don't use too much water, as it might deform the box. We chose to decorate the boxes later with self-adhesive wallpaper.

Step 2: Front Side Frame

We want to make a square "frame" at the front of the storage unit. This not only looks nicer but also significantly strengthens the structure.

First, draw parallel lines on the top flaps of the box in the pattern shown in the first image. If you examine the box, you'll notice there are two pairs of flaps that are opposite each other: left/right and up/down. For one pair of opposite flaps, draw four parallel lines 1” apart from the folding line as in pattern 1. For the other pair of opposite flaps, draw the parallel lines as well, but also mark two trapezoids on the sides as in pattern 2.

Cut along the black dotted folding lines with a craft knife to help you fold. DO NOT CUT ALL THE WAY THROUGH. Fold along the marks.

Use scissors or a craft knife to cut along the blue solid lines on each flap.

Fold both the pattern 1 flaps into the box along the folding lines. This will curl the flap into the box, so that it forms a rectangular prism bordering one side of the box. Then, fold the pattern 2 flaps into the box in the same way. This creates an interlocking structure that keeps the frame in shape.

We tried several different types of supports, and this one seemed to be able to hold the most weight without any tape or glue.

Step 3: Back Side Fold

Fold and interlock the flaps on the backside in as shown. 

Step 4: Decorate

Optional: Wrap self-adhesive wallpaper, wrapping paper, or tape around the box for decoration.

For wall display units: At this stage, you can set up what to display in each box as needed. This can also be done after the whole structure is completed. However, if a decoration is part of the box (e.g. I planned to make an infinity mirror box), it will be inconvenient to add after the whole structure is assembled, so you should make it at this step.

Step 5: Wall Display

Arrange the display cubes in the way you would like them to connect. We chose to make a 3x3 grid of diamonds (or a 1-2-3-2-1 pattern of squares) that would fold into a 3x3 grid of squares as shown, using 9 square boxes. 

To strengthen the connection, we added support sticks. Cut garden stakes or other strong sticks into sections as long as the depth of the display units.

Use awl to drill a pair of holes along the edge of each cube (see diagram). Put the zip tie through one hole into the box, around the stick, then out the box from the other hole. This should pull the support stick towards the edge of the box. If you are using jump rings, loop the zip tie around a jump ring. Connect the zip tie, but don't tighten it too much. 

Find the box you would like to connect to this one. Follow the same steps as in the first box. If you are using jump rings, instead of getting a new jump ring, loop it around the jump ring attached to the first box. If not, add another zip tie to link the zip ties on each box.

To hang the display cubes in the 3x3 diamonds formation, simply place two long nails into the wall beams to hold up the middle display cube.

Another way to arrange the display units is to just use 4 boxes. We decorated the boxes in red, yellow, blue, and white and outlined them in black, inspired by Mondrian squares. You can hang the completed structure up with chains/sturdy strings, with either one or two points of attachment on the display. By adjusting the attachment points and string length, you can hold the display in different forms. However, if there's a lot of weight on the display, you may need to fix the position of each unit on the wall rather than counting on the zip tie hinges to carry the whole load. 

Step 6: Infinity Cube

Another fun storage idea is turning eight storage units into an infinity cube. This allows you to create a variety of different shapes. Not only does this give the infinity cube a ton of different looks when decorated* but it also allows you to hide your items in plain sight with some of the forms!

*The infinity cube can morph into 6 different forms while undergoing the normal folding. That's 2 cubes and 4 2x4 blocks. However, you can get creative and only fold halfway, which can create L-shapes (as in the first image) and other shapes.

Step 7: Portable Storage Units

You can upgrade a regular storage unit to make it more portable.

One cardboard box sometimes is not strong enough to hold heavy objects. Here, we added extra support for some of the storage units so they could carry heavier objects. 

Cut out a 12"x12"x12" cube with two sides missing. This can come from the 12”x12”x18” or 12”x12”x12” boxes. Unfold the front side frame so you can insert the support into the storage unit. Folding the front side frame back. The corrugated lines on the outside cardboard box should be orthogonal to those on the cardboard inserts, as this will provide better support.

These units can be stacked up and help keep you organized! Since these boxes aren't connected to each other, it's very easy to unfold and flatten them, making them easily portable as well!

We liked this project a lot, as it's simple, fun, and has infinite possibilities! We hope you enjoyed it as much as we did!