Slip Casting as a Machine for Making Textured Ceramic Interfaces

Research Background and Problem

• Identified Problems or Challenges
  Ceramics is deeply embedded in daily life and holds significant artistic and functional value, but creating intricate textured ceramic objects manually can be labor-intensive, especially for novice makers. There is a growing interest in exploring tactile ceramic textures in the field of HCI (Human-Computer Interaction), but many existing methods rely on techniques like 3D printing, which often limits customization and material flexibility.

• Significance
  Textured ceramics have cultural and functional importance, influencing how people experience objects in tangible and sensory ways. Within HCI, textures are critical for enhancing tangible interfaces, evoking emotions, and guiding interactions through tactile feedback. Exploring new techniques to create ceramic textures advances creative collaboration between humans, tools, and materials.

• Research Motivation and Related Work
  Inspired by traditional slip-casting and its potential for customization, the authors aimed to develop a process that allows for easy and cost-effective creation of textured ceramic surfaces on reusable molds without the need for specialized templates. Previous HCI work explored different digital fabrication techniques, but few have leveraged traditional craft processes to expand the design space for ceramic-based interaction design.

Solution

• Proposed Method or Solution
  The authors introduced "Resist Slip-Casting," an adaptation of traditional slip-casting that uses water-resistant masking materials (e.g., vinyl stickers) to selectively control water absorption on plaster molds. This allows for the creation of customizable ceramic textures on the clay body during the casting process.

• Innovations

  1. Encourages customization of a single plaster mold to produce varying textured outputs.
  2. Simplifies the production of intricate textures and minimizes mold waste, compared to manual carving or embossed templates.
  3. Combines craft and automation, positioning resist slip-casting as a material-driven "fabrication machine" that fosters collaboration between humans and materials while retaining the essence of ceramics as a craft.

• Implementation Steps and Key Techniques

  1. Mold Preparation: Create plaster molds for vessels or flat tiles using CNC milling or traditional methods.
  2. Masking: Apply waterproof or water-resistant stickers (e.g., vinyl, paper) onto the mold to mediate water permeability.
  3. Casting: Pour liquid clay (slip) into the mold and allow clay to deposit on the plaster's surface, forming the ceramic body while being influenced by the mask.
  4. Demolding & Post-Processing: Remove the cast clay body, trim excess material, and refine texture details.
  5. Firing: Dry the clay object and fire it in a kiln for durability.
  6. Integration: For interactive applications, conductive traces and circuits can be added using conductive ink and glazed surface refinements.

Research Outcomes

• Specific Outcomes

  1. Development of resist slip-casting, enabling makers to create personalized textured ceramic objects from reusable molds.
  2. A library of ceramic textures encompassing shapes, patterns, symbols, and functional holes.
  3. Demonstration of resist slip-casting in tangible applications such as tactile graphics, interactive MIDI controllers, and decorative home products (e.g., bowls and lampshades).

• Advantages Compared to Existing Solutions

  • Unlike digital fabrication techniques like 3D printing, resist slip-casting provides a cost-effective and scalable solution that uses existing craft processes while supporting intricate texture creation.
  • Promotes sustainable craft practices by repurposing molds for multiple outputs.
  • Requires fewer intermediate templates, enabling rapid prototyping and more experimentation for makers.

• Experimental or Evaluation Results

  1. Resist slip-casting textures exhibited bleeding effects, which affect the sharpness and resolution of textures. This is framed as a unique aesthetic signature of the process.
  2. Testing across different masking materials revealed trade-offs: vinyl offered sharper textures but was harder to demold, while paper masks produced softer finishes.
  3. Applications like tactile graphic books and textured bowls showed feasibility and versatility in practical scenarios.

• Limitations and Future Directions

  1. Thin-walled ceramic objects prone to warping during firing, requiring additional expertise or kiln furniture to mitigate deformation.
  2. Small and intricate textures (e.g., Braille dots) often lose definition or tactile clarity due to material bleeding.
  3. Future work could explore larger clay structures, more complex masking geometries, varied clay types (e.g., terracotta), and integration with sensing technologies for interactive applications.

The study offers valuable insights into blending traditional ceramic craft with customization and experimentation, advancing both craft practice and HCI applications. Future explorations of resist slip-casting could deepen its capabilities in physical fabrication while continuing to reflect on the nuanced partnership between makers and materials.