Saggars & Saggar Making

Saggars (around 50 years old in 2015) in the cobbled yard at Gladstone Pottery Museum
Saggars, about 50 years old in 2015,
at Gladstone Pottery Museum, Longton
Photo: Terry Woolliscroft Collection  Date: 2015

Gladstone Pottery Museum is home to the largest collection of used biscuit and glost saggars in the world. The majority of the saggars at the museum came from the Garfield Works, Uttoxeter Road, Longton in November 1974. They were rescued by Gladstone's volunteers before the Garfield site was demolished.  more here


"One of the essentials in a successful pottery business is a good saggar"

The saggar is an open-topped clay box, in different shapes and sizes, made of fireclay or saggar marl with added grog of pre-fired clay or finely crushed used saggars. It was specifically manufactured to contain pottery during a biscuit, glost or sometimes decorating fire in a bottle oven. From the word 'safeguard.'

The saggar protects the pottery ware it contains from contamination created by oven's combustion gases and ashes, and the action of the flames.

Saggars of a particular shape and size have particular descriptive names:
  • Ovals
  • Doodle - half the size of an oval saggar. Peculiar to Alfred Clough
  • Banjos 
  • Hillers 
  • Cheese saggars
  • Square saggars
  • Skimmer saggars
  • Cup height saggars
  • Scorer saggars
  • Pigger saggars
  • Dottey saggars
  • Draw-through
  • Bidles
  • Dish saggars
More here> in The Potbank Dictionary.

MAU'ING THE SAGGAR  A film by Gerald Mee, 1981

The process of saggar making by the late Ralph Wheeldon - one of the four last saggar makers in the Potteries working at the Gladstone Pottery in Longton during the making of the film in 1981.


1986 Ralph Wheeldon entertains the crowds at the Garden Festival

Saggar maker Ralph Wheeldon at National Garden Festival Stoke 1986
Saggar maker Ralph Wheeldon at National Garden Festival Stoke 1986
Photo: Terry Woolliscroft Collection  Date: Summer 1986


Very short, 25 second, movie


Saggar making and bottom knocking in Stoke-on-Trent - a guide to early saggar technology.
By Paul T. Nicholson, Professor in Archaeology, Cardiff University

Most excellent and highly recommended written record of how saggars were made, together with details of the types of clay used.

Published 2011
Starts on Page 705 of the pdf

Here are edited extracts from the pdf, courtesy of Paul T. Nicholson

The clay used to produce saggars was known in Stoke as “Saggar Marl” and was mixed with grog ... in the pottery industry it can mean any none-plastic material. In the case of saggar marl the grog often comprised pieces of brick, old saggar  fragments and sand. The proportion of grog to clay varied according to clay type but could be as high as three parts grog to two parts clay ...

... saggar marl was delivered to the factory six or seven tons at a time, usually as lumps of 56 lbs each (25.40 kg). It was of two distinct compositions 'side marl' which was used for the walls of the saggar and 'bottom marl' used for the bases. Bottom marl had more grog mixed into it and the grog was of larger size than for the side marl. The six ton delivery would be divided into three tons of side and three of bottom marl. The two types of marl were dumped on the workshop floor and each would then be 'knocked with the mau' until it stood about waist high.

At this stage most of the air would have been knocked out of the clay and the individual blocks would have been amalgamated into a single pile of side marl and another of bottom marl. However, in times before pre-mixed clay was brought to the factory, the mixing of grog with clay was done on site. A layer of grog was spread on the floor, and on top of it a layer of ground clay, another of grog and so on 'till the pile is 1 ft. 6 in. (45 cm) to 2 ft high (60 cm)'. It would then be 'dug over' and sprinkled with water before being run twice through the pug mill.

Once the clay was prepared the first task was to work it on a bench. The bench was flat and had a metal frame which could be dropped over it. The bench was first wetted using a sponge and then sprinkled with sawdust until completely covered. Earlier in the 20th century, and before, sand had been used to sprinkle on the bench but health and safety considerations had led to the use of sawdust as it gave rise to less dust and so reduced silicosis.

Individual slices of clay were now cut from the side marl pile, or 'dump', using a tool known as a 'grafter'. This is a spade-like tool with a flat D-shaped blade, the curve of the D being uppermost and attached to the handle (or 'stale'). These slices were cut to be only slightly thicker than the depth of the frame on the bench top. The slices were placed into the frame each running from the back toward the worker and each slightly overlapping the other by 1 to1.5 inches (2.54 – 3.81 cm). The grafter was used to trim off excess thickness in a process known as 'fettling off' and then the slices (or 'bats') were hammered down using the flat blade of the grafter such that the overlapped edges became compressed together and the whole sheet of clay was reduced to the thickness of the frame. The frame usually had only 3 sides, that nearest to the worker being open. It was not always necessary to fill the whole frame and the saggar maker used the grafter to trim the edges square where the frame was not completely filled as well as to trim the
edge nearest to him. The normal depth of a frame was 0.75 inches (1.90 cm).

With this done, the edge nearest the saggar maker was thickened slightly with the fingers and the whole clay sheet again sprinkled with sawdust. A mau’ was then used to strike along the clay, working across it horizontally, gradually moving in rows from back to front. The mau' itself was shaped like a warming pan and comprised a cylindrical head made from heavy oak through which the shaft passes. The flat ends of the cylinder were used to hammer the marl. The mau' as kept in a bucket of water to keep the oak head damp and to keep the wood expanded so that the stale did not come off. This practice of soaking the mau' led to handles becoming rotted and causing accidents when they broke. By the time saggar making ended as a practice the wooden handles had been replaced by metal ones. The wetting of the mau' also meant that the clay and sawdust did not stick to it when used to hammer them down into the frame.

Mr. Wheeldon (saggar maker) describes the action of 'mau'ing in' as striking the clay and pulling sideways and forwards, in other words drawing the clay to the side of the frame and toward him. Each blow overlapped the previous one to its left or right (depending on the direction of mau'ing) and one or more of those above it. The marks from each strike were very clear (as visible in the films) and it was obvious to the worker where the next strike was to be.

Once the frame was filled the saggar maker took his measuring stick and marked the clay ready to cut into strips of the desired height for the wall. A rule, actually a wooden straight edge, was then aligned with the measured marks and struck so that it adhered to the clay whilst a blade was drawn through it to cut it into strips. The cutting was done with a tool known as a 'splice'. In recent times this tended to be an old hacksaw blade which had been bound with tape or otherwise given a handle. Mr. Wheeldon estimated that it took eight minutes to fill the frame, mau' it in and then cut out the sides.

The individual strips, still laying in the frame, were once again dusted with sawdust. A blade, known as a 'running under stick' was drawn underneath the first strip of clay, that nearest the saggar maker, to loosen it from the bench and it was then rolled around a wooden drum. These wooden drums had a circular, oval or other shaped cross-section with solid top and base (save for a hand-hole). Their walls were built up from laths to give the overall shape. The drum is placed onto the clay and rolled along the strip rolling the clay strip around it.

Whilst this process was going on another worker, the 'bottom knocker', working at a separate bench would be using the bottom marl to prepare the base of the saggar. He too used a metal frame but this time it comprised the complete shape of the base. He used a single piece of clay somewhat thicker than the frame ring and hammered it to the correct thickness using the mau'. The film shows that the thickness of the base could be slightly greater than that of its frame. The frame was then used to help to slide the finished bottom from the workbench onto a perforated metal plate known as a 'shord'. Once on the metal plate the frame is removed and the plate carried over to the 'wheelie', a turntable on which the saggar will be completed. It took approximately three minutes to knock a bottom.

The drum with clay wall wrapped around it was now carried over to the wheelie and placed on top of the prepared bottom which was of slightly larger  circumference than the drum and the wall (side) wrapped onto it. The wall is now cut where the two ends met and moistened before being beaten back together. This was to ensure a strong join in the wall.


Quote from Alan 'aj' Colclough, January 2016

My first job was at the NEWFIELD POTTERY of Alfred Meakin (Tunstall) Ltd. I was the lodge boy, and I had to count all the broken saggars and the ones still in use, every week.  Then I had to  report it to the lodge man LEN HILTON. He would then enter the lost ones in a great big ledger book - and would check for re orders.  That was the time when they did control losses.


At Gladstone Pottery Museum, 25 April 2015


Almost all saggars were marked in some way by their maker. Some with a simple cross, others with an elaborate impressed stamp. Here are just a few from the collection at Gladstone Pottery Museum.

Gladstone Pottery Museum
Saggar with 'backstamp'
Photo: courtesy Phil Rowley Date: June 2019


Saggars in a Garden Wall,  John Street, Longton
Photo: Source unknown  Date: unknown

Saggar walls
Behind the church off  Summerbank Road, Burslem
Photo: Source unknown  Date: unknown

Unknown location
Photo: unknown source  Date: unknown