How to Use Fosshape for Sculptural Encaustic Art

Disclosure: Wonderflex World sent me one yard of Fosshape to review for this post.

Are you excited to explore the creative possibilities of Fosshape? In this guide, you’ll learn how to use Fosshape to craft lightweight, durable 3-D structures that can be painted and transformed into stunning sculptural encaustic art.

About Fosshape

Fosshape by Wonderflex is a felt-like thermoplastic fabric that is widely used in the theatre industry for costuming, props and set design, puppetry, millinery headpieces, masks, sculptures, and more. Fosshape can be cut with scissors, sewn to itself and other fabrics, and shaped into stand-alone structures. Fabric steamers or heat guns are used to set the material into a stiff, rigid shape. The level of stiffness is achieved by adjusting heat and pressure.  

For artists interested in experimenting with sculptural forms, Fosshape offers exciting possibilities. Its ability to hold its shape after heat activation makes it a versatile base for painting, encaustic applications, and mixed media techniques.

Materials You’ll Need

To start your Fosshape project, gather these materials:

• Fosshape 300
• Heat source: Heat gun, embossing hot air tool, or fabric steamer
• Cutting tools: Scissors, pins, needle, and thread
• Paints: Encaustic gesso, chalk paint, or cold-water dyes (optional)
• Mixed media supplies: Compatible with encaustic
• Encaustic medium

Safety Tip: While heating Fosshape, work in a well-ventilated space and wear a NIOSH-approved particulate respirator – remember you are melting plastic.

How to Use Fosshape for Sculptural Encaustic Art

Step 1: Experiment with Small Pieces

Before starting a full project, practice on small pieces of Fosshape to understand how it reacts to heat and shaping.

Step 2: Cut and Shape the Material

Cut Fosshape to your desired size and shape. You can drape it over a form, pin it, or sew it into place. Remember, Fosshape shrinks by up to 30% when heat-activated.

Step 3: Heat-Activate the Fosshape

• Hold a heat gun or embossing tool 6–8 inches away from the surface.
• Move the heat source in a flowing motion to evenly activate the material.
• Apply pressure for denser, stiffer results.

Be cautious to avoid overheating, which can create holes in the material.

Step 4: Paint and Add Encaustic Medium

Once the Fosshape structure is set, you can paint it with encaustic gesso or chalk paint. Then, apply encaustic medium or use mixed media techniques compatible with encaustic.

Tips for Working with Fosshape in Encaustic Art

• Lightweight Sculptures: Adding encaustic increases weight, so if you want lightweight pieces, consider begin with encaustic gesso or chalkpaint to reduce the amount of wax you’ll need to add.
• Custom Shapes: Create intricate designs by layering and attaching smaller pieces of Fosshape.

Example Project: Encaustic Petal Sculpture

Here I created a Fosshape structure with petal-like forms inserted inside. These were secured with encaustic medium. I haven’t yet decided how or if I will finish or display the piece.

Learn more about Fosshape

Explore more resources to deepen your knowledge:

• Where to Buy Fosshape
• The manufacturer’s Fosshape FAQs
• Helen Dannelly teaches an online Fosshape class
• Fiber Artist Leisa Rich has self-published three books about using Fosshape in art

Learning how to use Fosshape for sculptural encaustic art opens up endless creative possibilities. Whether you’re crafting standalone sculptures or incorporating Fosshape into larger installations, this versatile material is an excellent addition to your artistic toolkit.

While I personally prefer natural materials, experimenting with Fosshape has been an exciting journey. I hope this guide inspires you to create your own unique 3-D encaustic art pieces!