Slab Building - an introduction to basic hand building processes

Part 1 - slab built form and cylindrical slab built vessel

The Aim - to build two items.

The first item is a slab built form approximately 20-25 cm in height, but no bigger than 15cm across the base and using mitered joints and ensuring that these are thoroughly joined to prevent any joints opening up/splitting during firing.

The second item is a cylindrical slab built vessel with a diameter of no more than 20cm and a height of 15cm.

Item One - Slab Box Construction

I entered into this process feeling fairly confident, as I’ve built slab boxes before. However, unlike last time—when I prepared the slabs and left them for a few days to reach the perfect leather-hard stage—this time the slabs had only been rolled that morning and were dried quickly by the heater. They were still quite soft, which made them tricky to cut accurately.

Despite careful measuring and remeasuring, I found the sides still didn’t match up as precisely as I’d hoped. This was frustrating, as the success of this task relies heavily on achieving clean, symmetrical edges for a neat box form. I focused on cutting the 45-degree angles at the edges to create stronger joins, and this technique worked well overall. However, the softness of the clay made it difficult to get perfectly clean cuts, and I think I may have overworked the material in trying to correct it.

The finished form ended up being lower-sided than planned, mostly due to the amount of trimming required to level the edges. Although it wasn’t as precise as I’d envisioned, the process was a valuable reminder of how important timing and clay consistency are when working with slabs.

Item Two - Cylindrical Slab Built Vessel

The creation of the cylindrical vessel was a much more enjoyable experience. Freed from the constraints of achieving symmetry and sharp, precise edges, I found greater freedom in shaping and designing this piece. I enjoyed planning the form, cutting the clay, and joining the edges to create a continuous cylinder.

Inspired by Rob’s earlier carving demonstration—which reminded me of the Chinese paper lanterns from my childhood—I decided to experiment with slicing into the lower sections of the clay. These cuts created a silhouette reminiscent of a mountain range. I then pushed the clay outward from the inside, introducing varied depths and textures. The sliced areas naturally split during this process, resulting in a striking and organic effect.

The following day, I added the base (I had previously rolled out an additional slab of clay and allowed it to dry at the same rate as the vessel). Once ready, I cut and attached it carefully using the scoring and water method. I’m really pleased with the outcome of this piece and look forward to seeing how glazing will enhance the textures and layered surface.

Part 2 - Slab Built Lidded Box

The Aim

Drawing upon my experience gained so far, to create a slab built, lidded box that incorporates one or more of the surface text qualities you created during the texture workshop. Consider how the surfaces and textures may follow around the form and allow the quanlity of the clay to "speak".

Lidded Slab Built Box

At the end of the first day, I rolled out two slabs in preparation for creating textured surfaces. For the first slab, I rolled it to the same thickness as my previous slabs and then used a needle tool to score a pattern resembling bricks.

For the second slab, I decided to experiment with added depth. I rolled it slightly thicker than the first, then cut a series of brick shapes from clay offcuts from the previous exercise and inserted them into the slab in a brick wall-style pattern. To ensure the added shapes were secure but still raised, I rolled the slab again, maintaining a slightly thicker depth so the inserted bricks didn’t fully penetrate the surface.

This exercise allowed me to explore layering and relief textures, and I was pleased with the subtle three-dimensional effect achieved through the brick insertion technique.

However, the next day I realised that making the slabs differing thicknesses had been a significant

mistake. I cut out various tile shapes to construct a box, which for simplicity, I had decided to make it a square cube. While this choice did make the basic construction easier, the two different depths of walls created complications when scoring and attaching the pieces.

Attempts to force the vessel into a more angular shape negatively affected the pattern, and the lid did not fit well—it required considerable trimming and still appears messy. Overall, I was disappointed with the final form of this box. While I still appreciate the visual effect of the contrasting brick patterns, the shape and structure fell short of my expectations.