What is Delft blue?
Delft blue is earthenware made from low-fired clay, covered in white tin glaze and hand-painted with cobalt oxide. It is not porcelain, although in the seventeenth century it was deliberately sold as such: as Delfts porceleyn or Hollants porceleyn.
It belongs to the large family of tin-glazed earthenware, which also includes Italian maiolica and French faience. Strictly speaking, it means earthenware made in Delft. In everyday use, all blue-and-white pottery in the Dutch style falls under the name, including a lot of printed souvenir ware made abroad. The term is not legally protected, so a factory mark is the most important clue to origin.
- Body: soft and porous, yellowish to light red where chipped. Porcelain is white and glassy right through.
- Glaze: white from tin oxide, often with an extra gloss layer: the kwaart.
- Painting: by hand, in cobalt that is greyish black before firing and turns blue in the kiln.
Timeline of Delft blue
- Guido di Savino from Castel Durante works in Antwerp as a maiolica potter. Antwerp becomes the centre of maiolica in the Low Countries.
- Fall of Antwerp. Many potters move north: to Haarlem, Rotterdam, Gouda and Delft.
- Founding of the Dutch East India Company (VOC), with a chamber in Delft. Chinese blue-and-white porcelain arrives in large quantities.
- Delft potters cover objects entirely in white tin glaze. The result closely resembles porcelain.
- Chinese exports stop during the transition from Ming to Qing. Delft fills the gap.
- David Anthonisz van der Pieth founds De Porceleyne Fles on the Oosteinde.
- Peak according to Royal Delft: 32 pottery factories in Delft.
- Wedgwood launches English creamware: harder, whiter and cheaper.
- The 23 remaining factories must register their marks: Delft's only general register of marks.
- De Porceleyne Fles is the last factory left in Delft.
- Engineer Joost Thooft buys De Porceleyne Fles and revives hand painting.
- Royal warrant: De Koninklijke Porceleyne Fles, internationally Royal Delft.
- KLM hands out Delft blue miniature houses for the first time.
- Museum Prinsenhof Delft is closed for renovation; reopening planned for 2027.
How did Delft blue begin?
Italian tin-glaze technique reached the north via Antwerp. After 1602 the VOC brought Chinese porcelain to Holland, which Delft potters began to imitate. When Chinese exports stopped around 1647, Delft took over the market.
Chinese porcelain as the model
Making true porcelain was impossible here: the required china clay (kaolin) was missing. Delft potters therefore refined their earthenware: thinner walls thanks to a better clay mix, a fully white glaze and an extra gloss layer. The result was a convincing, affordable imitation of the kraak porcelain of the Wanli period (1573–1620).
Why Delft?
Delft had its own VOC chamber, giving potters direct access to the Chinese originals. The city also had many empty breweries after the decline of its beer industry; these spacious buildings suited kilns and drying lofts. That is why many factories carry brewery names, such as De Grieksche A and De Metaale Pot.
Delft's golden age
Between roughly 1650 and 1750, Delft was the largest centre of tin-glazed earthenware in Europe. In 1670 there were 28 factories; around 1700 the number rose above thirty. Together they made millions of objects a year. About ninety percent was ordinary tableware; the decorative pieces in museums are the exception.
The exact peak differs by source: Royal Delft cites 32 factories in 1695, delftsaardewerk.nl speaks of 33 at the end of the seventeenth century.
Potters belonged to Delft's Guild of Saint Luke, alongside painters such as Johannes Vermeer. From 1654 a master potter had to pass a test with three prescribed objects. At the court of William III and Mary II, Delft blue became fashionable; Adrianus Kocx of De Grieksche A supplied monumental tulip vases, a pair of which in the Royal Collection stands 147 cm tall.
How is Delft blue made?
Clay is shaped and fired a first time into biscuit. It is then dipped in white tin glaze, painted by hand with cobalt and fired again at around 1000 °C. Only then does the grey cobalt turn blue. Historically the whole process took about two weeks.
Mixing and kneading clay
Local clay, German clay and marl from Tournai were mixed, washed and kneaded barefoot by the clay treader.
Throwing and moulding
Throwers made plates on the wheel; moulders made vases and figures in plaster moulds.
First firing
After drying, the ware was fired at 800–1000 °C into hard, pale yellow biscuit.
Glazing
Dippers immersed the biscuit in a bath of tin glaze made of lead, tin, sand, soda and salt.
Painting
The painter worked on the powdery glaze, which absorbed the paint instantly. Corrections were impossible. Patterns were transferred with a pounce of pricked paper.
Kwaart and glost firing
A layer of transparent lead glaze added gloss. Protected in saggars, the second firing followed at around 1000 °C.
Sorting
Everything was inspected: first-choice ware, second choice or rejects.
How Royal Delft works today
Clay is cast in moulds and, after a first firing, painted by hand. A painter becomes a master painter after about eight years of in-house training. Since Thooft, painting is done on a white, harder clay under a transparent glaze, no longer in unfired tin glaze.
Which colours does Delftware use?
Blue defines the look, but from the mid-seventeenth century Delft factories also made green, yellow, purple and orange. These grand feu colours survive the high firing:
Around 1700 petit feu was added: red and gold, with a third low-temperature firing, to imitate Japanese Imari porcelain. Extremely rare is black Delftware (c. 1700–1740): only 65 to 70 pieces are known worldwide.
Forms and objects
- Tulip vases and flower pyramids — tall vases with spouts for single flowers, c. 1688–1710.
- Tiles and tile panels — with children's games, ships and biblical scenes, often with corner motifs.
- Plates and dishes — from tableware to decorative dishes with landscapes by Frederik van Frytom.
- Apothecary jars — with a cartouche for the name of the remedy.
- Figures — cows, shoes, birdcages and even violin shapes.
How do you recognise genuine Delft blue?
Look at the body, the brushwork, the factory mark and the kiln marks. Since 1879 every hand-painted Royal Delft piece carries a small bottle, the monogram JT and the word Delft, with the painter's initials and a year code.
- The body. Yellowish or red clay indicates earthenware; a white, glassy break indicates porcelain.
- Brushwork. Handwork shows thick and thin lines and varying shades of blue; printed ware is uniform.
- The mark. Compare with reliable lists of marks. An old mark that looks very crisp is suspicious.
- Kiln marks. Old pieces often show three small scars from the pins in the saggars.
Example of a year code: the letters AW stand for 1927. The full list is on the Royal Delft website.
Decline and revival
European porcelain (Meissen, c. 1710), cheap English creamware and import bans in England and France pushed demand down. Around 1750 there were just over twenty factories, by the end of the century eleven, and around 1840 only De Porceleyne Fles.
In 1876 engineer Joost Thooft bought that last factory. He chose a harder white clay after the English example and restored hand painting. With Abel Labouchere he built a world-famous brand: a Grand Prix in Paris (1900), the royal warrant (1919) and today the Royal Delft Museum at Rotterdamseweg 196.
Delft blue today
Besides Royal Delft, Koninklijke Tichelaar in Makkum, documented since 1572, still makes tin-glazed earthenware. Blue and white has become an emblem of the Netherlands: from the KLM houses (since 1952) to fashion and design. Much of what is sold as Delft blue is in fact machine-printed and made abroad.
Glossary
- tin glaze
- Lead glaze with tin oxide, giving an opaque white layer.
- kwaart
- Transparent lead glaze applied as a gloss layer over the painting.
- biscuit
- Earthenware that has been fired once and is not yet glazed.
- pounce (spons)
- Pricked paper used with charcoal dust to transfer a pattern.
- kraak porcelain
- Late Ming Chinese export porcelain with a border of panels.
- glost firing
- Second firing at around 1000 °C, in which the glaze melts.
- grand feu
- Colours that survive the high firing: blue, green, purple, yellow, orange.
- plateelbakkerij
- Workshop or factory producing tin-glazed earthenware.
Frequently asked questions
Is Delft blue porcelain?
No. Delft blue is tin-glazed earthenware. The name "Delft porcelain" was a seventeenth-century sales term; true porcelain requires kaolin and a much higher firing temperature.
When did Delft blue originate?
The first potters worked in Delft around 1600. The breakthrough came around 1647, when Chinese porcelain exports stopped and Delft took over the market. The golden age ran from about 1650 to 1750.
Why is Delft blue blue?
The colour comes from cobalt oxide. Before firing the paint is greyish black; only in the kiln, at around 1000 °C, does it turn blue.
How do you recognise genuine Delft blue?
Look at the body (yellowish or red for earthenware), brushwork with thick and thin lines, the factory mark and three small kiln marks underneath. Since 1879 Royal Delft has marked its pieces with a small bottle, the monogram JT and the word Delft.
Does a seventeenth-century Delft blue factory still exist?
Yes. De Porceleyne Fles, founded in 1653, is the only surviving seventeenth-century factory in Delft. Since 1919 it has been called De Koninklijke Porceleyne Fles, internationally Royal Delft.
Sources
Consulted in October 2026. Museum collections and factory archives took priority over general websites.
- How was Delftware made? · delftsaardewerk.nl
- History · Royal Delft Museum
- Year codes and trade marks · Royal Delft
- The Rise and Fall of the Delft Potteries · Aronson Antiquairs
- Pair of tulip vases c.1694 · Royal Collection Trust
- Brown and Black Delftware · Aronson Antiquairs
- Creamware · Encyclopaedia Britannica
- Renovation · Museum Prinsenhof Delft
- Delftware · Wikipedia