Nerikomi: The Complete Guide to Japanese Marbled Ceramics

Nerikomi is a Japanese ceramic technique in which coloured clays are layered, compressed and then sliced, so that the pattern runs all the way through the body of the piece rather than sitting on its surface. Break a nerikomi bowl in half and the pattern is still there in the cross-section. Break a glazed one and you find plain clay under a coloured skin.

That single fact is what makes the technique worth understanding, and it is why no two nerikomi pieces can ever be identical.

How is nerikomi made?

The process is closer to laminating than to painting.

1. Colouring the clay. Raw clay is divided and each portion is wedged with a different stain or oxide until the colour is even throughout. This is the slow part. Colour that is not fully worked through will show as streaks later, and there is no fixing it once the block is built.
2. Building the block. The coloured clays are stacked, rolled or folded into a loaf. How the maker stacks them determines the pattern. A simple stripe is a stack of flat sheets. A chevron is that same stack, cut and reassembled at an angle. A checkerboard is a stack cut into columns, rotated and restacked.
3. Compressing. The loaf is pressed to drive out air. Trapped air becomes a void, and a void becomes a crack in the kiln. Compression also distorts the layers slightly, which is where nerikomi gets its characteristic waver rather than mechanical straightness.
4. Slicing. Thin cross-sections are cut from the loaf. Each slice reveals the pattern in the block. Slices from the same loaf are related but never identical, because the block deforms with every cut.
5. Forming. The slices are laid into or over a mould, or joined edge to edge, and worked into the final shape. The seams must be closed completely or they open during firing.
6. Scraping back. During forming the pattern blurs, because clay smears across the surface as it is worked. The maker scrapes the surface back to sharpen the pattern again. How deep they scrape changes what you see, since the pattern extends through the thickness.
7. Drying and firing. Slowly. Different coloured clays shrink at slightly different rates, and where two colours meet, that difference creates stress. A clear glaze is often used so the clay colour reads true rather than being altered by a coloured glaze.

Every step reduces yield. Pieces crack, seams open, patterns muddy. A maker working in nerikomi expects to lose work that a maker throwing plain clay would not, and that loss is carried by the pieces that survive.

Nerikomi, neriage, agateware and marbled glaze: what is the difference?

These four terms get used interchangeably online and they are not the same thing.

The practical distinction that matters when you are buying: nerikomi, neriage and agateware are all made from patterned clay. Marbled glaze is plain clay wearing a patterned coat. It is a legitimate technique and it can be beautiful, but it is a fundamentally different amount of work, and it wears differently. A chip in marbled glaze reveals plain clay underneath. A chip in nerikomi reveals more pattern.

Why are nerikomi pieces more expensive?

Because the pattern is built rather than applied, and because the failure rate is higher.

A decorated piece can be thrown quickly and painted quickly, and if the painting goes wrong you wipe it and start again. In nerikomi the pattern is created before the object exists, so a mistake at the block stage is discovered several hours of work later, when the piece is already formed. Add losses to kiln cracks at seams and at colour boundaries, and the cost per surviving piece rises sharply.

You are also paying for something that cannot be reproduced. Two customers buying the same nerikomi design receive genuinely different objects. That is unusual in manufactured goods and it is the entire proposition. The broader economics of this, and when mass production is the smarter buy, are covered in handcrafted versus mass-made.

Where does nerikomi sit among ceramic techniques?

It helps to place it against the alternatives, because "handmade ceramic" covers a lot of very different work.

Against hand-painting: painting is faster, allows fine detail and figurative imagery, and can be corrected. Nerikomi is slower, geometric or organic rather than figurative, and cannot be corrected. Our ceramics collection includes plenty of hand-painted work, and holding one of each side by side is the clearest way to understand the difference.

Against glazing effects: a reactive or marbled glaze produces unpredictable beauty at the surface, cheaply. Nerikomi produces controlled pattern through the body, expensively.

Against terracotta work: terracotta is lower fired and more porous, and its appeal is the warmth of the raw clay colour. It is a different proposition entirely. Our guide to stoneware, porcelain and terracotta explains how firing temperature drives everything about how a ceramic behaves.

How do you care for nerikomi ceramics?

Treat it as you would any handmade ceramic, with one addition.

• Hand wash. Dishwasher detergent is abrasive and repeated cycles dull the surface over time.
• Avoid thermal shock. Do not take a piece from a cold shelf and fill it with boiling water. Warm it first.
• Expect variation, not defects. Slight differences in pattern, colour depth and wall thickness between pieces are inherent.
• Watch the colour boundaries. This is the nerikomi-specific one. If a piece is ever going to fail structurally, it will most likely be along a line where two clays meet, because they shrink at slightly different rates. Handle accordingly.
• For planters, check drainage. Standing water is the main cause of damage to any ceramic planter.

Our full handmade ceramics care guide covers stain removal, storage and which imperfections are normal.