Friday, October 12, 2012

Film Guide: How to Paint a Rubber Knife to Look Real

I would like to start by saying that I never thought I would be able to do this by myself. I have no formal training in special effects what so ever. I ordered some rubber knives for my upcoming film RedFall and had them sent out to someone with better knowledge of these types of things and paid them to paint the knives to look more realistic. I was fairly satisfied with what I received. However, over time I noticed they did not shine in the light as if a real steel knife would. That being said, I gave this a shot and in about an hour, I had a rubber knife that looked real and shined just like it needed too.

I have looked all over the internet and have found tons of people looking for realistic looking prop/fake knives. All the ones I have found cost hundreds of dollars. I have also found people trying to make a fake knife for their films. However, I always see someone making something cheap looking out of cardboard or some other crap material. In this guide, you will be able to make something easily and cheaply and have it look damn good, in my opinion.

First, you need to find yourself some kind of knife made out of rubber, possibly a training knife. You could also use a knife that was made for Airsoft. Cold Steel makes good rubber training knives and swords. They are the best and affordable place I could find on the internet.

Cold Steel Training Gear

Unpainted Cold Steel Rubber Training Knife

Second, you will need some supplies. You will need some Silver Metallic Powder. This will provide that metal look you’re going for.

Alumilite Silver Metallica Powder

You will also need some clear coat acrylic spray paint. The spray paint is what gives the knife the shine you are looking for. Lastly, you will also need a brush to apply the powder and some painters tape.

The third step is applying. Once you have your knife and supplies, use some painters tape to wrap the handle so you don’t get silver and/or paint all over it. Apply the silver metallic powder to the knife’s blade with your brush. Once you have the whole thing covered and looking good, spray a small coat of the clear acrylic paint over everything you powdered. Let the knife dry for about a half an hour and then remove the painters tape. Bam, you’re done!

The end result is something like this.

Rubber Knife After My Powder and Paint Job

Now for some comparison shots...

Comparison of Unpainted and Painted
Comparison of My Paint Job vs. the Paint Job I Paid for.

On a side note, one side of the Cold Steel knives blade has a hole and inside it says “Training Knife.” It might not be that big of a deal if you are not planning to do many close ups of the knife. However if you are, some sand paper should rub the words right off enough that after applying the powder and clear coat they won't be visible anymore.

I hope this guide helps you out and I hope it brings more life to your independent films. If you do end up using this guide to help your film out, drop me an email and let me know how it went.


Disclaimer: I am in no way responsible for how you end up using your prop/rubber knife. My guide is intended for the prop/rubber knife to be used in the filmmaking process. Any other use of the knife are solely the intention of the user that follows this guide.


  1. Will the knife still be bendy after painting it?

    1. The knife is made out of a hard rubber so it's not floppy. It will bend if you forced it to bend, but just wiggling it won't make it bend or flop around.