Cardboard Knife Prop

This is a cardboard knife I made using cardboard, glue, tape and the same method i've used to make a cardboard sword. This project takes about 2-3 hours but could take longer depending on how fast your white glue dries when applying it to the blade to sharpen it.

Hot glue gun

White glue(recommended)

Cardboard

Knife to cut the cardboard

Painters tape

Small wood dowels or #2 wood pencils

First draw the shape of the blade on a piece of cardboard and make the blade vertically about half a cm to 1 cm longer than you want, I would recommend single corrugation cardboard as it is easier to cut and bend. Once you cut the blade out, score the cardboard along the sharp part of the knife at an equalish distance the whole way as shown in picture 2, the scores do not have to perfect, they are just to guide the bends in the knife blade. To score cardboard means to cut it but not all the way. Then bend the cardboard along the score to open and loosen up the cardboard as shown in picture 3. Then bend the cardboard the opposite way as shown in picture 4. ( the scores will be on the inside of the blade so they won't be visible)Now make a another one but in the opposite direction so that both blade pieces compliment each other(picture 5).

To make your knife sturdy, you will need supports in it so it doesn't break right when you make it. But before that, squish the cardboard segment on the blades between the score you made(where you bent the cardboard in the previous step) and the sharp edge of the knife(in picture 2, this section is between the right side of the blade and the score). Next get a material to use as supports. I used thin wood dowels that I had laying around. The dowels are about the size of a #2 wood pencil. You could also just use some cardboard pieces as supports. Next cut the dowels in the angle of the blade and glue it to the blade, as shown in pictures 2-4. Next glue the other blade piece to the supports and after that glue the 2 blade parts together and press them together to let the glue settle as shown in pictures 5 and 6. By now you should have a sturdy blade which looks unfinished. On the back of the blade, if there are any holes or places where the cardboard blades are supposed to have supports(probably on the tip of the blade) hot glue the hole to fill it up as shown in picture 7.

First we need to cover up the ugly back of the blade. Cut out a strip out cardboard and smush it. Then peel off the corrugation of the cardboard to be left with one paper layer. Glue this thin strip to the back of the knife and cut around the knife to cover up the back. This is all shown in pictures 1-5. Next we make the sharp part of the blade sharper. Put white glue along the edge of the sharp part of the blade as shown in picture 6. Next tightly tape the blade to squeeze the glue inside the corrugations of the blade and glue them together so that it gets sharper and stronger. This is shown in pictures 7-9. Next cut a straight strip with a width of about 1 cm and a length of about 4 cm(longer is better). Squish this piece of cardboard. Now wrap this around the bottom of the blade and wherever the 2 ends meet mark it(shown in picture 11). Now where the line was drawn to the edge of the excess cardboard, take off the corrugation as shown in picture 12. Now glue the strip to the bottom of the blade.

Get a piece of cardboard the length you want for the handle. Then wrap it around the wood supports tightly and glue the cardboard handle edge to where it meets the rest of the piece as shown in picture 5. Next wrap the cardboard around the handle to your desired thickness and mark where you want the piece to end. Next remove the corrugations from the back of the cardboard along the line where you marked and just about an inch from the line cut the cardboard and glue that inch with white glue to the rest of the handle as shown in the pictures. The inch of just paper gives a nice transition and smooth feel to the handle.

First cut out a hole in the shape of the wood dowels as shown in pictures 1-3. Then slide the dowel inside the hole. Cut the cardboard piece smaller as shown in picture 5. Next glue the cardboard piece to the blade and cut the piece around the blade to make a nice finish in the shape of the blade as shown in picture 7.

The bottom of the handle is kinda ugly so lets fix that. First, there's a big hole so patch that up with hot glue but try not to glue the handle to the supports. Obviously the glue will latch on to both so after this whole step like finishing the bottom, pull it as hard as you can to separate the handle and the blade. If you want to know more look at step 7 and if you think this is pointless, just leave the handle onto the blade. Next glue a piece of cardboard to the bottom of the handle and cut around the handle to cover up the hole as shown in pictures 3-5.

Connecting the handle without glue is important because it allows for the handle to come off in case something inside breaks and you need to replace it. To connect it tightly, get a scrap piece of paper or cardboard that's the length of the handle, and it should be thin because the handle already fits well with the dowels. Next wrap the paper around the dowels and push the handle onto the dowels to create a tight fit as shown in the pictures.

The knife is done! I hope you enjoyed making this cardboard knife prop and I hope the instructions weren't too confusing.