Tag Archives: chemistry

Friday Link-o-Rama

Just a reminder that there’s little more than 25 days left to enter the Prop Building Guidebook Contest! You can’t win if you don’t enter. I also wanted to ask a favor; if you have already bought your copy of the Prop Building Guidebook, head on over to the Amazon page (or to whichever store you bought it from) and leave a rating or a comment. I also have a Facebook page where you can tell me what you think. I’d love to hear what you like about the book, what you don’t, and how you’re using it. Now, onto the links!

David Katz has a website with a lot of information centered around his “Chemistry in a Toy Store“. It has some pretty fascinating articles about how common chemical toys work, such as Silly Putty, Slime, Shrinky Dinks, and the like. What is even more useful is if you scroll down, you will see Chemistry in the Toy Store Recipes; Katz shows how you can use common household ingredients to make things like slime, ooze, disappearing ink, various putties and more. Props people need these recipes all the time, and Katz is the chemist who originally came up with most of them.

Phil Obermarck is a sculptor who runs a blog, and he has an in-depth article about his experience using Jesmonite. Jesmonite is a gypsum-based acrylic resin that can be used with fiberglass. Unlike typical fiberglass resin (usually a polyester resin), Jesmonite is water-based and contains no solvents, which gets rid of a LOT of the health and safety hazards inherent in using fiberglass (though certainly not all of them). It unfortunately looks as though it is only available in the UK and Europe, though you can get comparable products in the US (Aqua-Resin being among the more popular).

Photographer Andrew Scrivani has an interesting article in the New York Times on how to choose props to improve food photography. While few of us may be propping a food photo, the ideas he shares are just as useful for anyone dressing a set or designing the props in a scene.

The original Frankenstein movie was a hallmark in special effects makeup as well as set dressing (try to think of a science laboratory that hasn’t been influenced by this film). So how cool is it to see behind-the-scenes photographs of Frankenstein and similar monster films?

Review: Costumes and Chemistry by Silvia Moss

I only recently came across this book for the first time. I’ve never noticed it before because of the title; if I had seen it before, I would have assumed it dealt only with costumes, not props, and I would have moved right along. Make no mistake though, this book is vital to the props maker. It actually contains almost nothing about making clothes or fitting actors or even that much about fabrics and sewing. Instead, Costumes & Chemistry: A Comprehensive Guide to Materials and Applications, by Silvia Moss, covers all sorts of paints, adhesives, and plastics (in both sheet and casting form) which the prop shop uses. Though the examples shown are mostly costume props and accessories and giant character heads and suits, you can very easily apply it to many of the props you need to build.

Costumes & Chemistry reveals a lot of research and development. It turns costume crafts and props into more of a science where the materials are thoroughly tested and described, rather than a hodge-podge of traditions and assumptions swirling around in each person’s head. Moss talked with chemists, technicians, salespeople and manufacturers of many of the materials you use from basically every company you’ve ever heard of who makes these materials. Armed with a number of grants from UCLA and interviews with so many people working in the field, she has created a reference book that should be on the shelf of anyone working in props and costume crafts, as well as those interested in cosplay and convention costumes, replica prop making, LARP, and even model making.

Costumes and Chemistry by Silvia Moss
Costumes and Chemistry by Silvia Moss

Part 1 of the book is brief, providing much of the same safety information found in Monona Rossol’s book. The bulk of the book is divided between parts 2 and 3, or materials and applications.

The section on materials divides them into categories such as paints, adhesives, plastic sheets, and thermoform plastics. For each type of material in these categories, Moss gives the brand names of the various products that she tested, examples of why and how they are used, a description of the physical properties, how to clean them up (where applicable), precautions and health and safety information, where to buy them, and what sizes and forms they come in. This isn’t where you will find information about making props from paper plates and pipe cleaners; this covers all the modern materials you’ve used or read about such as Sintra, latex foam, leather dye, Kydex, etc.

In the section on applications, Moss breaks down how many example costumes were made. These include costume accessories, headpieces and jewelry from Las Vegas revues, Broadway musicals, advertising characters in commercials, various mascots, and other venues. This section provides some illustrations giving general techniques, but for the most part, it discusses the applications of various materials through very specific examples from a wide variety of craftspeople. Some of the pieces chosen for the book are quite recognizable, and it can be interesting and surprising once you find out what materials and techniques were used to create their look.

Costumes & Chemistry was published in 2004, so it should remain up to date for awhile. I could see an update in a few years to include new formulations of current materials and new brands (as well as the deletion of defunct brands; Phlex-Glu, for example, is listed in the book but no longer produced). For the most part though, most of these materials have been in use for several decades now, and barring some dramatic new invention, should remain in use for several decades more.

So Many Chemicals in the World

54,973,018. That’s how many registered organic and inorganic substances there were in the world when I wrote this sentence, according to the Chemical Abstracts Service (CAS). The Toxic Substances Control Act (TSCA) gives the EPA in the United States the authority to maintain an inventory of all chemicals used in commerce (excluding chemicals used in foods and food additives, pesticides, drugs, cosmetics, tobacco, nuclear material, or munitions). To date, their inventory contains 84,000 such chemicals. Over 1670 of these are considered hazardous substances which your employer is required to inform you when you are working with them. You’ve probably seen products which state “This product contains a chemical known to the state of California…” There are somewhere in the neighborhood of  750 chemicals listed under California’s Proposition 65 which are known to cause cancer or reproductive toxicity.

Of course, over 78% of the high volume chemicals produced have not had even basic toxicological testing (see Toxic Ignorance, published by the Environmental Defense Fund), let alone testing for carcinogenic properties. “High Volume” of course does not include all 84,000 chemicals used in commerce; in 1990, that list included a mere 2971 chemicals. In other words, around 653 chemicals have been tested for their toxicity by 1990. What a far cry that is  from the 54,980,438 registered chemicals in existence (when I wrote this sentence). Some estimates put the total amount of chemicals tested worldwide for carcinogenic properties at around 900. Nine hundred out of nearly 55 million.

What’s a props person to do? When you look at all the products you use – spray paints, adhesives, epoxies, mold-making and casting, coatings, sealants, resins, foams, cleaners, and so on and so on – and count up all the various chemicals contained within, you could have hundreds of hazardous and carcinogenic substances which you are exposed to on a daily basis. If you wish to make a career of making props, that could mean several decades of exposure. It adds up quickly.

One shouldn’t generalize about safety, because proper safety procedures involve specific actions for specific chemicals. But if one were to distill down the essence of safety it is this: don’t breathe anything but air, and don’t get stuff on you. Always use the least-toxic product in every situation. Often, the only benefit of a more-toxic option is speed, or ease of use. Formula 409 may cut grease faster and with less effort then soap and a scrubber, but soap will not be absorbed through your skin and cause reproductive harm.

In the brief time it took you to read this article, around 24 chemicals have been added to the CAS database. As I write this sentence, the number stands at 54,980,470.

How to Make Stage Blood

Asking how to make fake blood is kind of like asking how to make food. Sometimes you need a light breakfast, sometimes a heavy dinner. You need to ask yourself what the blood needs to do. While trying out new recipes can be fun, it is not terribly useful unless you know what you are trying to achieve. So when dealing with making stage blood, I will first look at the preparation you must do, than introduce some of the basic chemistry which can lead to some blood recipes for you to try.


The three aspects of preparation are research, planning, and experimentation. You need to research what the effect will look like. Even if you are not going for a realistic effect, you want a reference image or images which you’ve shared with the director and the rest of the production team so you are all on the same page. The last thing you want is to show the director the results of your hard work and have her go, “That’s not what I was picturing at all.”

Planning is also vital. There are hundreds of blood recipes with countless variations, all designed for specific needs. What does your blood need to do? Does it get in the actor’s mouth? Does it need to be washed out of the costumes? Does it run freely or pool up into puddles? Is it just a liquid or does it have chunks in it? If you can plan out what the blood needs to do, you may find that you can use different recipes for different effects, or fake some parts with less expensive paint or dye. Do a break down of all the effects in the show and determine what each needs to do individually.

The final step is to experiment. No matter how great your blood recipe is, there are just too many variables in a show to not test out a number of options. The stage lights will affect the color of your blood; it may look great in the shop, only to appear purple once on stage. The color of the costumes or set may also require some tweaking to the blood’s color. As with any prop, you often want to present your director with a number of options to choose from.


There is no one-size-fits-all recipe for stage blood. Many theatres and prop people have developed their own formulas and keep their secrets jealously guarded. There are a number of recipes you can find to use as a starting point. With a bit of knowledge of chemistry, you are armed with a repertoire of techniques which can be expanded as you gain more experience.

Essentially what you need is a thick, gooey base with a colorant added. The most basic recipe is corn syrup (Karo Syrup in the USA, or Golden Syrup in the UK) and red food coloring. You can add a bit of blue or even green food coloring to refine the color. This recipe is edible, which is good if the blood is used around an actor’s mouth, but since it is organic, it can attract insects and vermin, and will rot after a time. It is also sticky, messy, and will stain clothes and skin.

If you want to avoid stains, you will need to add some form of soap to the blood mixture. This will help limit the colorant from attaching to the fibers of the clothing. Liquid color-safe bleach or dish soap work well. You can use a “no-tears” baby shampoo if the blood has the possibility of getting near anyone’s eyes. You can experiment with colored soaps too. Green or blue dish soap, or Simple Green, can be used to tint the red food coloring. It is essential to work with your costume department whenever the blood is coming into contact with costumes. They can scotch guard the areas that will receive blood beforehand. They can also throw the costume into a bath of cold water with lots of stain remover as soon as it gets off stage. You may still need two or three backup costumes. The other problem with any soap-based blood is that it will lather if you rub it too much.

If you want to limit the potential for staining further, you need to look at your colorant. Different brands and types of food coloring have different staining potentials. As an alternative, you can substitute children’s non-toxic poster paint, or other washable art products.

Powdered gelatin, instant pudding, or cocoa powder can be used as thickening agents in lieu of or in addition to corn syrup. Corn starch or flour will also thicken your mix. Creamy peanut butter will both thicken and darken your mix. Interestingly, the protein in the peanut butter makes it easier to wash out.

If you want your blood to congeal or clot during the scene, there are a number of ways to do that. The instant pudding mentioned above will coagulate like real blood. KY jelly will make it clot after a period of time as well. If you thin the blood with cheap vodka or other alcohol-based products, it will congeal over time. A little unflavored gelatin will turn your blood into scabs.

A touch of mineral oil will give it some sheen and help catch the lights. Adding glycerin on top will also give it a fresh and shiny appearance and improve the surface tension.

Further Reading

There is a lot more reading to be found across the internet, with recipes utilizing any number of ingredients for various effects. As long as you do your homework beforehand, you should have no problem coming up with the right recipe for your effect.