This is an armor technique that only really works for simple armor shapes.  In this case, all the armor is formed of simple shapes that are curved.  It is quick, easy, and cheap to make, but not as durable as fiberglass or Friendly Plastic armor.

Make your patterns

As with all my armor, I start by making patterns of the pieces I will need.  I generally do this by starting from a rough sketch, which is then scanned, cleaned up in Inkscape (vector drawing program), then printed back out.

Cut out insulation foam shapes

Hot wire cutters are great for cutting insulation foam.  They’re silent, and give a fairly nice edge, but they will release toxic fumes as you work.  Be sure your work area is ventilated, or work outdoors.  You could also use a Dremel or a router to cut the foam shapes out.  If you are working with a fairly extreme curve, you may want to cut shallow channels into the foam to let it curve easier in later steps.  This is shown in Gourry’s thigh guard:

Thigh armor - polystyrene sheet to cover a foam sheet.  The grooves in the foam let me curve it along its length.

Coat with plastic sheeting

Because insulation foam isn’t very impact resistant, I glue a layer of plastic to the outside surface of it.  This also lets me curve the armor as desired.  In this case, I’m using 0.02″ high impact polystyrene – this is the same type of sheeting you might use for vaccu-forming, and is available from many retailers, including US Plastics.  I cut it to the approximate shape of the armor.  If you want to make it exact to the curved shape of the armor, you can, but it is easier to cut it slightly smaller than the armor part.  This will leave a vulnerable ridge of foam around the outside of the armor, but it is far easier.  Alternatively, you can cut the plastic slightly larger, glue it into place, then trim the plastic with scissors or an Xacto knife.

Once the plastic sheet is cut to the shape, you can use hot glue to apply it to the armor.  While gluing the sheet on, also curve the foam into the desired shape.  Once the glue dries, the plastic sheet will force the foam to keep the curve.  I put the grooves onto the outside of the curve of the armor.  This let me force the foam to a greater curve than if the grooves were on the inside.

Shoulder guards

Coat with craft foam

The plastic sheeting from the above step gives us strength; craft foam will give a smooth surface.  For this, we can stretch the craft foam over the armor, then use hot glue along the sides of the armor to glue it into place.  At corners, you may have to cut the craft foam to let it lay flat, or you can gently heat the craft foam and stretch it over curved edges if needed.  This will give the armor a slightly soft surface, smooth out small imperfections, and hide the plastic sheet.  Once the outside surface is coated, we can cut craft foam shapes to coat the inside surface, if needed.


Attach hooks for mounting the armor

My preferred method of attaching armor to my costume is using lanyard hooks from the craft store.  They are lightweight, can be bent as needed, and don’t take up much space.  They can be backed up with velcro as needed.  To attach, I hot glue a small rectangle of the plastic sheet to the mounting area, then hot glue the lanyard clips to the plastic.

Hooks on shoulder armor to attach to the chest straps

Coating the craft foam

Craft foam doesn’t take paint very well – at this point, you should use Mod Podge or a varnish to coat the craft foam.  If the color is correct for your armor, you could even be finished at this point.   I used a gloss varnish, which left the armor parts slightly shiny.

Armor set, first application of gloss coat


Options to paint the armor are fairly open – spray paint, hand painted enamel or acrylics, etc.  I used FolkArt acrylics in this case.



For protecting the paint, you should use a sealent on top of any paint job.  Automotive clear-coat is durable and shiny, or there are many matte, semi-gloss, and gloss options at various craft stores.