Cardboard for prototyping presents 3 big advantages:

it’s cheap

it’s sturdy

it’s recyclable

It’s one of the most practical skills you can learn for designing products. Almost free, easy to find, easy to manipulate, cardboard prototyping is also super fun.

Where to Find Cardboard for Free?

Besides looking around your house, there are a few ways to get cardboard for free. Ask you local grocery stores and supermarkets (Walmart, Costco) if they have boxes to spare. Best timing is in the middle of the day or in the evening when staff is stocking shelves and hence emptying boxes.

For large size free cardboard: try kitchen stores, bike stores and dollar stores. However, many stores are not allowed to give away boxes because they have agreements with recycling centers.

2 online free cardboard resources:

Craigslist: look up “free moving boxes”

uHaul exchange program: a directory of people who just moved out and want to get rid of boxes

Free cardboard is cool because, well, it’s free but it’s not always the best for prototyping as it comes already used, folded and printed on.

For better prototypes, you will need clean large sheets of cardboard with a neutral tone or in plain color. I detail below the main types of cardboard (cardstock, chipboard, corrugated and honeycomb) and where to find each of them.

Choose your Cardboard

First and foremost, you need to choose the type of cardboard that will work for your project.

The word “cardboard” is just a generic term that doesn’t say much. It defines a paper that is thicker than 200 GSM (grams per square meter). This article will help you understand the different types of paperboard.

Assuming you already have a prototype idea in mind, maybe some drawings and even schematics of how your product could look like, cardboard can then be used to visualize your idea in space and create a first 3D visualization, or even mechanical prototype of your idea.

Type of cardboard you use will greatly change your ability to fold, bend, glue, draw, drill or paint it.

Criteria to pick your cardboard:

thickness

Thinner cardboard (such as cardstock or chipboard) is easier to fold, lighter and better for details. Thicker one (such as corrugated fiberboard or honeycomb board) is more sturdy, resistant to impact and allow for bigger projects.

surface

A white or brown surface will change the overall aspect of your prototype. Coated surfaces (such as cardstock or white liner chipboard) are easier to print on or use stickers on, brown ones (such as corrugated fiberboard) easier to paint on.

sturdiness

Prototypes made for demo or exhibitions require a stronger material and well-finished details (with colored cardstocks for example). Furniture, objects carrying weight need sturdy cardboard as well (such as honeycomb board or corrugated fiberboard).

Let’s see what your options are. I compare

1 – Cardstock

The thinnest type of cardboard is simply called cards. They are the type used for making business cards, catalog covers, postcards or playing cards.

Cardstock is an excellent type of board for prototyping. It’s sturdy but easy to cut and drill, has a great smooth surface, comes in multiple colors, is pretty inexpensive and easy to find. Tools to work with cardstock are the usual suspects: scissors, utility knives and pens (see part 2).

Cardstock suppliers

Neenah, Array, Wausau, American Crafts and GP are the main brands of cardstocks. Sheets usually come in big stacks of 100 or 250 sheets, in packs of white or colored cards. Standard card size is 8.5 inch x 11 inches.

White:

Neenah: 250 sheets of white 65lb cardstock costs about $12

Wausau: 250 sheets of white 110lb cardboard costs about $14

Color:

Array: 100 sheets of 10 color cardstock is also around $11

American Crafts: 60 sheets of heavy weight color cardstock for about $12

2 – Chipboard

White Lined Chipboard (abreviated in WLC, GD, GT or UD) is usually made from recycled paperboard. It’s made of a top layer of bleached pulp and a middle and back layer of recycled waste paper. One side is coated multiple times, and the other side only once. Inside is grey. White back version is known as Triplex board.

White Lined Chipboard advantages are its price and its printing abilities. It’s an inexpensive type of cartonboard that is also great for prototyping. It’s easy to draw on, glue and cut. Sheets are thin and easy to fold while sturdy enough for small prototypes with details.

Thicker than cardboard, chipboard is typically a good paperboard for cutting typography and decorative details to add to your prototype. I detail in part 2 of this article what are the best cardboard cutting tools.

Below are some examples, such as these letters cut in chipboard:

Or this sheet of chipboard cut in the shape of a vintage frame. Top layer is made of cut cardstock glued on the chipboard and then painted with silver spray.

Holes have been punched in the sheet of chipboard below to prototype future stamps:

Chipboard suppliers

Chipboard sheets are usually more expensive than cardstocks because they are thicker and need multiple treatments, even if recycled.

EcoSwift: 200 chipboard sheets 8.5 x 11 inch for about $22

ThunderBolt Paper offers slightly bigger sheets, but for a much bigger price (25 chipboard sheets 12×18 inch for about $25).

3 – Corrugated Fiberboard

Corrugated fiberboard is the king of paperboard for prototyping. It’s also used for final products.

It’s made of corrugated board, a wavy-looking board called the “flute”, sandwiched between two pieces of linerboard (usually kraft linerboard). The flute is made of a kraft containerboard usually over 0.01 inches (0.25 mm) thick. Overall sturdiness and thickness of corrugated fiberboard varies from 1/32 inch (0.8 mm), called “F” flute, to3/16 inch (4.8mm) for a “A” flute. Most common corrugated cardboard is “C” flute, with a thickness of 5/32 inch (4.0 mm).

Primary use of corrugated fiberboard is to make boxes, which is why it’s so easy to find and popular among product designers. It’s a strong and versatile cardboard that has interesting design properties.

Corrugated fiberboard is strong enough for final product. It lets air flow while offering great see-through capabilities, depending how you cut it.

Google launched Cardboard, a low-cost DIY Virtual Reality headset made out of thin sheets of corrugated fiberboard. You can make Cardboard yourself or buy a kit online. I AM CARDBOARD store is specialized in Google Cardboard headsets.

Artist Chris Gilmour creates giant sculpture out of cardboard, like this impressive wheelchair:

Pieces of laser-cut corrugated cardboard assembled in a geodesic sphere prototype:

Corrugated cardboard suppliers

For nice large clean sheets of corrugated cardboard (not moving boxes), count about $16 for a pack.

Neutral brown:

Inergroup Packaging: 8 sheets of corrugated cardboard 1/2 x 11 inch for about $16.99

Aviditi: 5 sheets of corrugated cardboard 48” x 24” for $16.36

Color:

Hygloss offers colored corrugated sheets 8.5 x 11 inch for about $8 a pack

4 – Honeycomb Board / Hexacomb

Honeycomb board, also called Hexacomb, is a type of corrugated cardboard that is particularly rigid. It’s a grid of honeycomb-like paper sandwiched between two sheets of light cardboard. It can be use in indoor and outdoor projects, has a strong resistance to impact. Surface is smooth and solid.

Honeycomb board is used in automotive, packaging, industrial design and construction. It requires strong tools and space to work with.

Cardboard bicycle functional prototype made by English designer Phil Bridge out of Hexacomb. Waterproof, it can resist a daily use up to 6 months.

Dutch artist Filip Jonker made the “De Furie”, a cardboard boat out of honeycomb board, as a way to demonstrate cardboard sturdiness and durability.

Honeycomb board suppliers:

Hexacomb is the company making honeycomb boards, contact them for custom orders.

MrBoxOnline sells hexacomb panels (1 sheet of 40x48x1 for $11)

To sum up

Type of cardboard Description Type of prototype Suppliers Cardstock Thin paperboard that comes in all colors / easy to find Ideal for lettering and details as well as smaller prototypes made on a desk Neenah (white) / Array (color) Chipboard Thicker recycled coated paperboard with white and/or brown sides / requires good cutting tools such as rotary cutters or laser-cutters Ideal for small sturdy prototypes / Easy to paint and print on EcoSwift Corrugated cardboard Very thick and sturdy popular cardboard / Easy to find Ideal for prototyping and even final products / Can be used in many ways Inergroup Packaging Honeycomb board Extra sturdy thanks to the honeycomb shape of the board Used for large-size strong prototypes Hexacomb

Do you use cardboard for your prototypes? Share your experience in the comments below!

Part 2 of this series is about cardboard cutting tools for prototyping: “How to Cut Cardboard”

Part 3 is about Various Cardboard Shaping Techniques