Using EVA Foam for Costume Accessories, Hats & Headpieces: Part I
What is EVA Foam?
I first became acquainted with EVA foam about 12 years ago at a trade show and since that time it has become a staple supply in our work room. We began using it for character heads but soon discovered that it had so many possibilities in other aspects of costuming. And we are constantly finding new uses for the product.
"EVA" stands for Ethylene Vinyl Acetate. When formulated into a closed cell foam product, it takes on the following characteristics which are of great advantage to the theatrical costumer.
This extremely dense foam can be found in many commercial applications from handle grips to flotation safety devices to sports safety equipment. We have found that EVA foam readily accepts paint, glues and various finishes which makes it ideal for costume accessories and props.
Although we have been using EVA foam for many years, the idea for this tutorial came about just recently. We had a production of "Man of LaMancha" to get ready for shipping. When I pulled the armor for the Knight of the Mirrors from storage, I saw that he was in desperate need of a new helmet. There were only a few days before we needed to ship the show. Not enough time to make a fiberglass helmet. And, of course, my neighborhood armorer was out of the helmet style that I wanted in size 7¾. So I decided to use EVA foam to get this job done.
Adjust Your Thinking
If you have had experience making hats and headpieces out of traditional materials (ie., buckram, willow, felt, etc.) you have a good basic foundation for working with EVA foam. You will, however, need to make some adaptations to your to your way of planning and patterning your project. Please note that all of the comments and instructions that I will be making are based on using 4lb. (the density) ½" thick EVA. Although it can be obtained in other densities and thicknesses, we have found that the 4lb., ½" EVA is the most versatile for our needs.
One of the first things you will notice is the fact that most projects will be slightly larger in scale than the same item built using traditional methods. The side bands of hats will be wider than the width of the head. Brim edges will be thicker. Pattern dimensions will need to be adjusted to compensate for the expansion and contraction of the foam when forming a curved or tubular shape. However, all of these attributes can be offset with careful planning, design and patterning.
Lets try an example. You need a pillbox hat to fit a 23" head. Using traditional patterning and construction methods, you would pattern the piece to have a round or oval tip 23" in circumference and a sideband with a finished length of 23". Try this with ½" EVA foam. Cut your circle and sideband. When you try to attach the sideband to the ½" edge of the tip, you will see that the sideband is too short to completely encircle the tip. This is due to the fact that as you form the flat piece of foam into a tube, the inner surface contracts and the outer surface expands. In order to make the sideband fit completely around the circle you need to add 1.5625" to the length of the band. It may take a few trials before you begin to feel comfortable with this adjustment in scale, especially if you have made hats before. But I think you'll find the effort and practice are worth it.
For more information about hat patterns and hat making I recommend "From the Neck Up"1. This book is my bible for hats and headpieces.
The Right Tools for the Job
Two of the most important skills for working with EVA foam are accurate marking and accurate cutting of the pattern pieces. EVA foam has many wonderful properties, but it is very unforgiving when it comes to sloppy workmanship. Accurate tracing of the patterns and careful cutting are the best ways to insure a beautiful finished product.
The photo at the right shows a selection of the tools that we have found to be most useful for marking and cutting EVA foam.
Use an extra-fine point marker for tracing the pattern pieces onto the foam. This gives you an exact line for cutting. The heavier marker is used for marking the balance points of the pattern. We have found that the Sharpie® brand of permanent marker is the best tool for the job.
|Click on any of the photos for a larger version|
Cutting & Marking Tools
"Measure Twice, Cut Once"
This is rule that every carpenter knows and abides by. In short, it says "be accurate". EVA foam is a wonderful medium, but care must be taken. Sloppy marking and cutting can result in a less-than-perfect finished product. Be precise in your patterning. Trace your pattern pieces onto the foam carefully. And make your cuts smoothly.
For the most part you will want your cuts to be as close to perfect 90° angles to the face of the foam as possible. Use the X-acto® Foam Board Cutter for this job. You will also want your cuts to be as smooth as possible. Always use sharp blades. Change them as soon as you begin to feel any resistance as you make the cuts. Rough, irregular cut edges will result in a weak bond when you glue to two surfaces together. Fig. 1 shows poorly made cuts (top) and properly made cuts (bottom). Remember, "practice makes perfect".
All of your cuts should be made with a smooth, confident motion. Start your cut about a blades width before your marked line and make the cut in a continuous motion from start to finish. If you must stop in mid-cut, DO NOT remove the blade from the work. Finish your cut slightly beyond the end point of your marked line.
TIP #1: Keep your eye on where you are going with the cut. Concentrate on the line just before the knife blade. Where you are and where you've been will then take care of themselves.
Bevel cuts are the most difficult to make cleanly and smoothly. Use the X-acto® Matt Cutter for this. We have tried both the plastic model and a plated metal model. The plastic model works best since it slides more smoothly over the surface of the foam. The metal body catches and drags across the foam. And although the Foam Board Cutter comes with a 45° attachment, the blade is not long enough to cut completely through the foam.
The second photo at the right shows the pieces needed to make the great helm. Except for the vision screen and tip, all of the pieces are cut x2. It is always a good idea to flip the pattern when tracing the second of two pieces so that the pair of pieces form a mirror image. That way you know you have a right and left piece. This practice also allows all balance marks and assembly keys to be on the working side of the piece. It is simply a good habit to acquire. The pieces are as follows:
TIP #2: When assembling the foam components, keep all markings on the outside of the piece. If you are worried that any markings will be visible in the final piece, use a colored marker in a shade close to the final color of the object. The Sharpie® markers come in a range of colors from black through yellow.
Parts of the Great Helm cut from ½" EVA foam (except Vision Screen which is cut from plastic needlepoint canvas)
Stick to It
Just as careful cutting is important, so is the choice of adhesive. A good contact cement is what is needed. We use Master® Quick Drying All-purpose Cement1. This is a brand that is used in the shoe industry and has exceptional strength. It dries quickly and has a high tack. Although we have had adequate results with other brands, we prefer the Masters for overall workability and performance.
Coat the edges to be bonded with a smooth, even coat of glue. Neatness does count. Allow the glue to set completely until it is dry to the touch. Align the edges of the foam and press then firmly together. I have found that if you have a flat surface to work on it is much easier to get the pieces in proper alignment. With the two pieces to be joined laying face up on the surface, I start at the point farthest away from me and "walk" the two edges together toward me. This technique is especially good when joining edges that are opposing curves. As you walk the pieces toward you the joined curve will just pop-up into position.
TIP #3: Always work with the right side of the piece facing up. If any of the edges are mis-aligned, it is better that they be on the wrong side of the finished piece.
You basically have one, and only one, chance to make the join. If the edges become mis-aligned, do not pull them apart and try to re-align. When you do this, the glue threads and will make a very weak bond when re-joined. To separate a glue joint use acetone to break the bond. Then reapply the glue, allow to set-up and make the join again.
There Is a Method to These Things
In all types of construction, whether you are working with wood or fabric or any other material that can be cut and assembled, there is an order of construction that will dictate the outcome of the project. This is no less true when working with EVA foam. Follow the steps in order and the outcome is predictable. Rearrange the order and you may find that the construction process becomes more difficult than necessary or that the final object is different than originally conceived.
For this project the order of assembly is as follows:
1. The upper edge of the top sideband is cut at a 45° inside bevel so that when the tip is attached the resulting join forms a sharply defined transition between the two planes. If the edges were both cut at 90° angles, the transition would be a gentle curve.
2. The openings in the face guard are cut by using a ½" punch to make the top and bottom curves, then connecting the resulting holes with straight cuts. Freehand bevel the straight cuts slightly to the inside so that the grill bars are slightly narrower on the wrong side of the face guard. By doing this, the slit openings will maintain a constant spacing from outside to inside when the face guard is curved around the helmet.
Great Helm Foundation
Inner Supports in Place
Completed Great Helm with Crest Attached
Stabilize the Foundation
Now that the helmet foundation has been constructed, it is time reinforce and stabilize the helmet. Although the EVA foam helmet is very stabile it still has more flexibility than we really want in this project. Some kind of protective coating is needed to seal the foam and add some rigidity. The two products pictured to the right have solved this problem for me.
Sculpt-or-Coat®1 and Mod Podge®2, used alone or more usually in combination, are the solution. These products are similar to white glue. They are both water soluble and dry completely clear. They can be thinned with water if necessary. The main difference between the two products that I have found is that Sculpt-or-Coat® has a thicker consistency and retains brush strokes when it dries. Even when thinned with water it still retains a textural finish when dry. However, it tends to produce a more rigid finish. Mod Podge® on the other hand is thinner and self-leveling as it dries. This makes for a very smooth surface. By using these two products together you can have the best properties of both.
Begin by working on the interior of the helmet. First spray the entire inner surface with a flat black latex spray enamel. This not only finishes the interior but it also absorbs any light entering the helmet through the vision screen and aids in visibility for the wearer. When the paint has dried apply two coats of sealant. If using the products in combination, apply the Sculpt-or-Coat® first and then the Mod Podge®. Allow each coat to dry before proceeding with the next application. I use from 2 to 4 coats on the interior surface and 4 to 6 coats on the exterior surface. Usually I apply 2 coats on the exterior to seal the foam before I do any painting. This provides a good ground for the painting.
Coating products for EVA foam
Finishing Touches..."Should We Gild the Lily?"
The base coat is a flat black spray enamel. Allow to dry thoroughly. The metallic coat is then dusted over that base coat. If the metallic coat seems to be to heavy, the base coat can be lightly dusted over the metallic to kill some of the shine. I usually do this while the metallic is still wet. I like the way the two colors mix.
On this project I wanted the heraldic crest to be of a slightly different color and texture than the rest of the helmet. Make It Stone® Metallic Textured Paint by Krylon1 was used as the color coat. Hot melt glue was used to draw on some of the details of the dragon's wings. And more texture was added by soaking lace motifs in Mod Podge® and gluing them onto the dragon body and wings. Most of the detail painting and any shading necessary to "pop" the details were applied with an airbrush. I used Createx™ Airbrush Colors2. They are available in both opaque and transparent formulations. To further dimensionalize the dragon I add highlights to the details I want to emphasize. On this project I used Liquigems™ acrylic glitter color by Liquitex®3 in gold and silver. The rivets on the helmet body were also added this way.
When these have dried it is time for one or two more coats of Mod Podge® to seal and protect the painting as well as add additional strength to the helmet.
There are many more uses for EVA foam in producing costume props and accessories. I hope this tutorial has spurred your interest in this product and technique. In Part II I will discuss the intricacies of fashioning period hats form EVA foam.
Helmet painted with a base coat of flat black
Metallic gold dusted over base coat and crest painted with Metallic Stone® textured spray paint by Krylon
Footnotes, Bibliography & Links
1 Thermoplastic Foam Industries - Australia
1 Dreher, Denise. From the Neck Up: An Illustrated Guide to Hatmaking. 1981 Madhatter Press
1 X-acto® is a trade mark of Hunt Mfg. Co., Statesville, NC 28677
2 Sharpie® is a trade mark of Sanford®, Bellwood, IL 60104
1 Master® Quick Drying All-purpose Cement is a trade mark of Petronio Shoe Products Corp., 305 Cortland St., Belleville, NJ 07109
1 Sculpt-or-Coat® is a trade mark of Sculptural Arts Coating, Inc.
2 Mod Podge® is a trade mark of Plaid Enterprises, Inc., Norcross, GA 30019
1 Make It Stone® Textured Metallic Paint is manufactured by Krylon Products Group, Cleveland, OH 44115
2 Createx™ Airbrush Colors are manufactured by Createx Colors, East Granby, CT 06026
3 Liquigems™ Acrylic Artist Color™ by Liquitex® are trademarks of Liquitex Artist Materials,
Piscataway, NJ 08855
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©Schenz Theatrical Supply 2002