Start by preparing a flat, stable work surface. A regular table is perfectly fine, as long as you have enough space to work comfortably.
Make sure your workspace has good lighting so you can clearly see every detail throughout the process. Prepare a trash container for foam scraps and other waste materials.
You can work at home, on a balcony, or outdoors, depending on the task. Avoid strong winds, as they can blow lightweight foam pieces around and interfere with spray painting.
IMPORTANT: Hot-wire foam cutting and aerosol spray painting require effective ventilation that removes fumes and airborne contaminants to the outside. An open window or a respirator alone may not provide adequate protection. Use appropriate respiratory protection and a suitable work area for these processes.

For my original TOXICAST artwork, I used an EPS foam sheet measuring 25 × 25 cm (approximately 10 × 10 inches), with a thickness of 5 cm (2 inches).
Using a ruler and a sharp utility knife, carefully measure and cut your foam into a square.
You can choose a different size if you prefer, but I recommend following my original dimensions for your first attempt.
Try to keep the edges as straight and even as possible. This will help the foam fit properly inside the casting mold later.

Before creating the texture, secure your foam sheet to the table to prevent it from moving while you work.
Cut two pieces of clear packing tape, approximately 50 cm (20 inches) long each.
Fold each piece into a loop with the adhesive side facing outward, connecting the ends together.
Attach both tape loops to the back of the foam sheet, then place the foam onto your work surface and press gently to secure it.
This simple method helps keep the foam stable without additional clamps or complicated tools.
Once the sculpting is complete, carefully remove the foam from the table. Test the tape on your work surface first to make sure it will not damage the finish.

Now comes one of the most creative parts of the process: shaping the three-dimensional texture.
Using a hot-wire foam cutter, gradually carve flowing, wave-like grooves and raised sections into the foam, following the movements demonstrated in my video.
Work slowly and smoothly, combining deeper cuts with smaller details to create a natural rhythm across the surface.
Your texture does not need to look absolutely identical to mine. Small variations are part of what makes each artwork unique.
Once you're happy with the result, remove the leftover foam pieces and clean your workspace.
SAFETY: Heating polystyrene can release harmful decomposition products. Use effective local exhaust ventilation that removes fumes outdoors and suitable protective equipment. If you cannot provide adequate fume extraction, use a non-heated sculpting method instead.

For the casting mold, I used white expanded PVC foam board approximately 3 mm (0.12 inches) thick.
First, cut a square base measuring 25 × 25 cm (approximately 10 × 10 inches).
Next, prepare four PVC strips for the side walls, each approximately 10 cm (4 inches) high. Measure their lengths according to how you plan to join the corners, allowing for the 3 mm thickness of the material.
Before taping everything together, position the strips around your foam model to check the fit. The foam should sit inside without large gaps or excessive pressure on the edges.
Cover the inward-facing surface of each PVC strip with clear packing tape along its full length. This creates a smooth barrier that helps reduce adhesion between the casting plaster and the mold walls.
Join the four walls using the same tape to create a square frame. Carefully seal the corners and bottom joints to help prevent the liquid casting mixture from leaking.
Finally, place the sculpted foam inside the assembled mold and check that everything is stable and properly aligned.

Before casting, prepare the foam texture and the inner walls of the mold with a suitable release agent.
Choose a product specifically compatible with polystyrene foam and gypsum-based casting materials.
Apply a thin, even layer according to the manufacturer's instructions, paying particular attention to the deeper grooves and narrow areas of the texture.
The release agent helps reduce adhesion and makes it easier to separate the finished plaster casting from the original foam model.
IMPORTANT: Some aerosol release agents contain solvents that can damage or dissolve EPS foam. Always test the product on a small scrap piece before applying it to your artwork.

Now it's time to prepare the casting mixture.
For this artwork, I recommend using a high-strength gypsum casting plaster suitable for detailed sculptural work.
Prepare a clean mixing container, fresh water, and a mixing tool dedicated to workshop use.
You can begin with approximately 500 g (1.1 lb) of dry plaster for the initial detail coat. Additional material will be needed to complete the full casting.
Measure the water and plaster according to the manufacturer's specified mixing ratio. Add the plaster to the water and mix as directed until the mixture is smooth and free of dry lumps.
The mixture should flow well enough to reach the fine details of your texture. Avoid adding extra water just to make it thinner, as this can weaken the finished casting.
Prepare only as much material as you can apply within the product's recommended working time. Never reuse mixing tools or containers for food preparation.

Start by applying a small amount of freshly mixed plaster directly onto the sculpted foam using a brush.
Carefully work the mixture into every groove, narrow channel, and detailed section. This first contact layer helps the plaster reach the entire textured surface and reduces trapped air pockets.
Be gentle around thin foam edges and delicate raised areas to avoid damaging your original model.
Once the detailed surface is thoroughly coated, slowly add more plaster to fill the mold to your planned backing thickness. Prepare additional batches if necessary, following the plaster manufacturer's instructions.
For reinforcement, you may use a fiberglass mesh specifically compatible with gypsum casting. For a 25 × 25 cm artwork, a piece approximately 22 × 22 cm (8.7 × 8.7 inches) may be suitable, depending on the casting thickness.
Embed the mesh inside the plaster, keeping it away from the outer surfaces and edges.
If you plan to hang the artwork, install a properly rated mounting system designed for the finished casting's weight. Do not rely on a loose hook or wooden stick simply pressed into wet plaster.
Finally, gently tap the mold walls or apply light vibration to help release trapped air. Leave the mold undisturbed once the plaster begins setting.

Place the filled mold on a flat, stable surface and allow the plaster to harden.
For this masterclass, you can plan approximately 24–48 hours before disassembling the mold, but always follow the specific plaster manufacturer's guidance. Setting time, safe demolding time, and complete drying time are not the same.
Once the casting is strong enough to handle, carefully cut the packing tape along the outside corners of the mold using a utility knife.
Remove the four PVC side walls one by one.
Place a flat, rigid support board against the back of the casting. Holding the assembly securely from both sides, carefully turn it over so the sculpted foam is accessible.
Slowly separate the foam model using gentle rocking movements, supporting the plaster to avoid cracking or bending.
Do not force the foam out if it feels stuck. Check for areas where the texture may be mechanically locked inside the casting.
Once the foam is removed, your three-dimensional TOXICAST plaster relief will be revealed.

Even after the casting has hardened and been removed from the mold, some moisture may remain inside the plaster.
This is especially important on the textured side, where the foam model may have slowed moisture evaporation.
Place the casting in a dry, well-ventilated area and allow it to continue drying.
Plan for at least another 24 hours, but keep in mind that complete drying may take considerably longer depending on the casting thickness, material, temperature, and humidity.
Make sure the artwork is thoroughly dry before painting. Remaining moisture can interfere with paint adhesion and affect the quality of the finish.

Now it's time to give TOXICAST its bold, vibrant color.
Place your completely dry casting on a protected surface in an area suitable for aerosol painting. Remove loose dust and, if necessary, apply a primer compatible with gypsum and your chosen spray paint.
Use appropriate respiratory protection and effective exhaust ventilation for spray painting.
Apply fluorescent orange spray paint across the entire textured surface.
Work in several thin, even coats, gradually reaching the deeper grooves and raised sections without creating drips or covering up the fine sculptural details.
Continue until the orange color looks bright, rich, and consistent.
Once you're satisfied with the coverage, allow the paint to dry according to the manufacturer's instructions. Drying and recoating times vary between products, so do not assume that one hour is always sufficient.

Once the orange base coat is ready for the next layer, position the artwork vertically or at a slight angle, making sure it is securely supported.
Take your fluorescent green spray paint and apply it from one side at an angle, following the technique shown in my video.
The goal is to highlight the raised areas of the texture while preserving the bright orange color inside the deeper grooves.
This creates the signature TOXICAST effect: vivid green highlights contrasting with the fluorescent orange background, giving the artwork an almost glowing, three-dimensional appearance.
Build the green color gradually and avoid covering the entire orange base.
When you're happy with the final result, allow the paint to dry completely according to the product instructions.