English and Dutch tin glazedTiles – circa 1650 – 1790

On this page you will find guidance on inherent defects, cleaning and repairing. Expert advice is always important when considering the conservation and maintenance of historic Delft schemes.

A Brief History

The history of what we have largely come to recognise as the seventeenth and eighteenth century tile work of Northern Europe is a fascinating trail of migration of communities and the techniques of tile making which travelled with them.

The Dutch and Low Country tradition first appeared in London during the mid sixteenth century as people fled the wars of religious persecution, however it wasn’t until the eighteenth century that the technique for tile making firmly established itself with centres in Liverpool, Bristol and London, thousands of tiles were also imported from Holland as the popularity of tiles which we know under the generic term of ‘Delft tiles’ took off.

By the mid eighteenth century the industry in England was at its height and, in addition to the home market, tiles were shipped in their thousands from the ports of Europe across the Atlantic to the Dutch and English east coast settlements of the New World.

Tile making continued in Holland, where it still survives. The English scene saw the slow decline and end of the ‘Delft’ tradition as the developments in the English ceramics industry began to produce the robust and distinctive product which eventually became the ‘Victorian tile’.

There was a brief revival of imported Dutch tiles between 1890 and 1910 when they were favoured by Morris and Co. and other Aesthetic Movement designers.

The Delft style of manufacture is broadly speaking a twice fired hand decorated tin glazed tile.

In Holland, Spain and Portugal elaborately hand painted tile panels were used as interior and exterior decoration in their own right. However, in England their use seems to have remained firmly utilitarian in dairies and kitchens but used more decoratively as fireplace surrounds.

Practical guidance on simple conservation issues.

The information on these pages is for guidance only we do not accept responsibility as a result of any person carrying out any works according to the advice contained in this web site. Always follow Health and Safety measures described on products, tools and materials. Jackfield Conservation Studio is not responsible for the work which you do, the responsibility is yours and yours alone!

Inherent defects.

Delft tiles are usually conserved with great care or taken out of their original location to be redisplayed as ‘art’ pieces. The instance of Delft tiles of any great quantity undisturbed in their original location in the UK is few.

The chief failure of Delft tiles is the inherent problem of glaze crazing and flaking away from the body. These tiles tend towards high porosity, friability particularly around the edges, and easy fragmentation. Much of the conservation work on seventeenth and eighteenth century tiles revolves around consolidation of damage which is as a direct result of the manufacturing technique.

They are also prone to moisture absorption which in turn can result in efflorescence caused by salt crystallization. Salt crystal growth can force the glaze to become detached from the body. This is a well known and understood problem with soft body ceramic objects. Moisture absorption also leads to the ready ingress of stains into the tile body most notably if tiles have been used to surround fireplaces.

The glaze itself is also soft and will readily become abraded on the surface, loosing the typical soft shine which tin glaze produces, and again leaving the glaze open to absorption of dirt.

Guidance on consolidation, cleaning and repair

The most damaging and frequently encountered of inappropriate repairs to Delft tiles is the use of Portland cement to either re instate loose tiles or install them in a new location subsequent to the failure of the original lime plaster fixative.

The relative hardness, lack of plasticity, and ability to hold soluble salts all combine to make the use of Portland cement as an adhesive for Delft tiles the most disastrous of inappropriate repair of which little can be done to rectify without some damage to the original tile material.

Cleaning

Delft tiles may be cleaned using a solution of de ionised water and a neutral ph detergent such as Synperonic A, usually a moistened soft cloth is sufficient to clean the glaze but particular attention can be paid to dirty grout lines using a tooth brush or similar. Buffing to a shine with a dry soft cotton cloth brings out the soft lustre of the glaze. If tiles are over wetted there is a danger that crystallization of soluble salts may take place, and if loose tiles are soaked over a period of time in distilled water to either remove salts or staining then care must be taken to dry the tiles quickly and effectively.

Organic staining, such as soot, if left alone, will continue to migrate into the tile body.

Removing organic and iron oxide staining is difficult and is the area of expertise of ceramic conservators.

Fireplaces

Eighteenth century tiles are quite commonly found as fireplace surrounds. Severe loss of glaze surface on hearth tiles due to abrasion is irredeemable. The most common problem is soot blackening at the edges of tiles; the worst effects of this can usually be removed as described but often the best option is to remove the old grout altogether and replace with new.

Repairing eighteenth century tiles

Paraloid B72 is a standard adhesive for Delft tiles; it may be applied, diluted in acetone, with a fine paintbrush around the fragile edges of distressed glaze and over vulnerable crazed areas. Restoration also works well as a form of conservation, filling missing areas of glaze or body clay is preferable to leaving damaged edges. White plaster of Paris infill where fragments are missing in a scheme will not greatly detract from the overall visual aesthetic. If the intention is to restore the colour and decoration to fragmented and missing areas of tiles then it is advisable to use an acrylic and calcium carbonate-based fine surface filler as it will provide a smooth dense surface finish for paint application. The decoration can then be applied using an acrylic clear glaze mixed with artists powder pigments to match. This repair work is usually done by an experienced conservator but can be done by amateur hand.

Maintenance

Good maintenance relies on positive action to maintain an ambient suitable environment, damp conditions with excessive moisture ingress into the mortar or substrate is the main engine of destruction.