Paper prototyping: Reinforcements and affordances

This is the third part of my posts which show some documented constructions I have made in cardboard. Previously we looked at the ideas of repurposing material and following purpose when creating. It ended with mentions of reinforcing weakpoints which we will take up in this post, along with taking advantage of the affordances present in the materials and constructions. We’ll take that up in this post.


I would not claim that any of these techniques are the definitive way to handle reinforcements, but from my experience these have served me very well. Let’s start with knowing tapes. I briefly mentioned the properties of scotch tape, though I prefer the use of masking or duct tape. Masking tape is much easier to handle as you can easily tear pieces for use and can in that case construct things a lot faster. Duct tape comes in a variety of materials and for different uses, but generally it’s a tape that has crisscrossed fibers which strengthen it’s ability to stay stuck to things. If you want tape that is dependable and would last through a lot of mistreatment then you should go with duct tape. For most situations and prototypes though, masking tape is more than enough.

With tape you can reinforce your constructions and make sure you have something stable in several ways. From the diagrams above we see four methods I use. The first is the cross or weave pattern made with the tape. The intertwining pattern makes sure that the tape isn’t removed as easily, and the object being made will have an extra layer of protection that holds with the effort of every tape. The next method shows a tape being reinforced on each end while holding two objects at an angle. The idea here is that the ends holding the objects together would not fray as easily and they act as support for the objects from being pulled apart against the direction of the tape holding them.

As you see the first two methods use more than one piece of tape to secure the tape itself. The next two are more focused on the physical structure of the tape. In instances where you are holding or binding two objects together with tape, you may use tape as you would a rope. Using a single piece of tape and wrapping it around is both very quick and an effective way to keep objects stuck together on one axis. If you bind objects horizontally, as shown in the diagram for example, it is still possible to pull the objects apart against the direction of the tape. So if you are using this method you will want to bind the objects vertically and across the top/bottom as well. Recently I have been attempting to make a cardboard chair which makes good use of this. You can see a photo of how it looks bound below.

Finally there is the pressing/crushing of the tape. The idea there is to have the tape hug the surface of the material and ensure the adhesive is pressed against and sticking well to it. You do this by running your finger/nails/folding bone through after the tape is placed, making sure to press the tape as close as possible into any corners/edges. When done well, there are no air bubbles where the tape is weak and it is not so easily pulled off or fraying. I emphasize this practice when prototyping because it is easy to miss pressing the adhesive into the material and as a result it makes for a weaker construction.

In progress shots of making a cardboard chair. The lower left photo shows something that already exists to pad packaging.

I will just mention here two forms of support structures that I have used in constructions that involve the use of cardboard. First is the use of a bent plate/bracket. Think of them more like a corner brace or bracket in furniture. You basically have a an extra layer of cardboard formed in the shape of an L that you add to a corner using tape. This reinforces the structure by adding an extra layer of the material that will need to break and also adds extra thickness. A small drawing of what it may look is below, and an example of it being used in a construction next to it. What you see in the photo are dice using augmented reality symbols. I stuck bent brackets inside each die using glue.

The second support structure which I have not used as much are cross-joint formations. You can see a photo of one that I have created below. This particular structure was made as a proof-of-concept, but was designed to be flatpacked down with a little bit of effort and patience. As you see in the lower left, the material was abused a little to create the pressure needed to hold in place. The grid-like structure can hold plenty of weight and if made with denser cardboard instead of cereal/pizza boxes would have been very strong as a construction. The strings were used to hold each of these pieces together, and there was enough to build two knee-high structures.

The proof of concept being used as a stand and able to take on a lot of weight.

This post became quite long, so we’ll continue in the next post. I plan at least one more post to talk about paper prototyping construction before we move on from the topic. Phew!


The paper prototyping series

Part I – Paper prototyping

Part II – Knowing your medium

Part III – Repurposing or following purpose

Part IV – Differences in the purpose approaches

Part V – Reinforcements and affordances

Part VI – Final thoughts on construction

Part VII – Chair epilogue

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