Labels, Marks, Signatures, and Signs

Marks and dating

In most cases, pontil marks, labels and signatures can give a good general idea when a piece was made rather than a specific date. It should be remembered that paper labels in particular could be attached to pieces after general use of the label had been phased out, such as using up of old stock at a later date. A signature engraved on an item sometimes has a specific year appended.

Quick links: Pontil Marks | Paper Labels | Marks incorporated into the design | Marks added using transfers | Signatures | Advertising Pieces


Pontil Marks

More pictures are available on page 134 of Mark Hill's book [1].

Broken pontil mark

Broken pontil marks were left when the pontil rod was broken off and left unfinished. These are characteristic of very early experimental pieces made in 1972 and early ranges made up to mid-1973. Some other later pieces have broken pontil marks, including some experimental and trial pieces, all attenuated bottles and the British Museum design. In the case of attenuated bottles, the base generally was too thin to grind flat and therefore was left untouched.

Broken pontil mark

This broken pontil mark was on an Aurene attenuated bottle.

Coachbolt pontil mark

Coachbolt prunt, used late 1973 only

The coachbolt prunt was used from mid- to late-1973 only. Here it is with Michael Harris's signature.

Bullseye pontil mark

Bullseye pontil mark

Thus far this mark has been seen on just a single piece, a very early test vase for the Azurene range. Therefore it may date from 1978. The vase was kept in the studio archive for over thirty years. Timothy Harris says that this mark was made by pressing a flat piece of iron on the base of the vase. The concentric circles were formed when the glass cooled. The remains of a broken pontil mark can be seen in the centre of the base.

Flame pontil mark

Flame pontil mark, with the flame part on the left hand side, used 1974 to 1979, last use 1982
Flame pontil mark, with the flame part on the left hand side, used 1974

The flame pontil mark, with the flame part on the left hand side, was used from 1974 to 1979, and much less frequently thereafter. Last use was about 1982. Therefore, generally speaking, the flame mark is a 1970s mark.

Note that the flame mark was also used by Kerry Glass, with the flame on the left hand side (early pieces) or the right hand side (from some time in the early 1980s to 1985). The tool supplied to Kerry Glass to make the mark was subsequently lost and re-made by them from an impression from existing stock. Hence the mirror image.

Following inquiries to IOWSG it has been established that the flame mark was not used by St. John's Crystal on the Isle of Man. St John's Crystal was never supplied with the embossing ‘Flame Logo’ tool and so it is not possible that items thus marked were made there. The tool was supplied only to Kerry Glass.


Paper Labels

  • Black flame on white vertical oblong label, 9.5 mm wide x 15.5 mm long, used 1973 to mid-1970s.
Oblong, black flame on white, 1973-1975

  • In the 1970s three white horizontal oblong labels with black text were used.
Small oblong, Handmade Isle of Wight

Small oblong label, 22 mm wide x 11 mm deep. This label was found on an early Tortoiseshell attenuated bottle, which may date from 1973 or 1974. It seems that labels with 'HANDMADE' as one word are earlier than labels with 'HAND MADE' as two words.

Small oblong, Handmade Isle of Wight and Flame mark label together

The two labels above were found together on a footed globe paperweight, possibly dating from 1973 or 1974.

Oblong, Handmade Isle of Wight

The label above is 31.5 mm wide x 9.5 mm deep, with 'HANDMADE' as one word. Note there is little gap between the two lines of text. This label is known from a Seaward globe vase made late 1973.

Oblong black flame on white together with Oblong Handmade Isle of Wight

The oblong label that says 'Handmade Isle of Wight' is sometimes found together with the flame label. It is also 31.5 mm wide x 9.5 mm deep. Note in this case there is a distinct gap between the two lines of text, which may indicate a later reprinting.

Oblong, Hand Made Isle of Wight England

The label with 'England' is the same size as the one immediately above. It is probably later than the label without 'England' since it has 'HAND MADE' as two words. Note also the comma after the word 'WIGHT'.


  • Black horizontal oblong label with white text, used late 1970s at least until 1979. This label has been seen on a piece simultaneously with the Design Council label shown below.
Black oblong, white on black label, late 1978s
Black oblong, white on black label, late 1978s

  • Triangular labels were used from 1978 to 1991. The label came in two sizes: large (34 mm corner to corner), which is rarely seen, and small (18 mm corner to corner), which is by far the most common. Thus far, examples of the larger label have been seen on a vase made in 1991 and on an Azurene 'Turquoise' vase made 1986-1987. Perhaps the larger label started to be used only from the mid-1980s.
Triangular 1980s label

  • British Design Council award label, 31 mm in diameter. Used 1979 and shortly thereafter on pieces of Azurene. The award certificate is on loan to Isle of Wight Museum of Glass. It is signed by the Design Council's chairman, Viscount Caldecote, and director, Keith Grant.
British Design Council award label

The British Design Council award label is also known paired with a label of St John's Crystal, Isle of Man.


  • Labels on a Lace Pink egg-shaped paperweight, including the label of the Design Centre London, c. 1988-1991.
Labels on a Lace Pink paperweight

  • Gold on black square label, 12 x 12 mm, used 1992-1995. This label was used mostly in 1992 and 1993. The second example shown here seems to be silver on black, but it is a trick of the light. It is also gold on black.
Gold on black square label, 1992-1995
Gold on black square label, 1992-1995

  • Black on gold square label, 12.5 mm wide x 12 mm high, used 1992-1995.
Black on gold square label, 1992-1995

  • Black on transparent plastic label, used 1992 to present.
Black on transparent label, 1992 to present

  • Black on gold rectangular label, 13.5 mm wide x 10.5 mm high, probably used about 1995-1996. This label is rarely seen. The design seems to be the forerunner of the label with 'The Original' added on the bottom shown immediately below.
Black on gold rectangular label, early 1990s

  • Black on gold square label, with 'The Original', used from 1996 to 2014. A new label was designed when the studio restarted production at Arreton Barns in March 2014, but stock of the old label was used up during 2014.
Black on gold square label, The Original from 1996

  • Gift of the Year 2001 was awarded to Wild Garden designed by Timothy Harris. The label is very rarely seen still attached to a piece, as it is in this example. It is 15 mm in diameter.
Gift of the Year 2001 label

  • 30th anniversary label, 14 mm wide x 26 mm high, used 2003-2004.
30th Anniversary label

  • First label designed for the studio after the move to Arreton Barns, used from late summer 2014 until summer 2016.
Black label, mid 2014 to 2016
Black label, mid 2014 to 2016

Silver label used from summer 2016
White label used from summer 2016
Gold label used from summer 2016

Silver, white and gold labels used since summer 2016. The choice of label depended on the glass piece to which it was attached, to avoid an excessive clash of colour.


Marks incorporated into the design

The IOWSG logo was incorporated into the design of (some?) early graal pieces by Jonathan Harris. It is known in a perfume bottle dated 1989 (image on the left), one of the earliest pieces of graal produced, and a bowl dated 1990 (image on the right courtesy of Sue Burt).

IOWSG logo incorporated in graal perfume bottle
IOWSG logo incorporated in graal bowl

Marks added using transfers

Liberty mark on a Librty Peacock Feather cylinder vase

The Peacock Feathers design for Liberty of London was produced between 1987 to the early 1990s. They had "LIBERTY" on the pieces, generally near the base. The picture here has been blown up to make it clearer. On the pieces themselves the mark can be difficult to see because of the combination of black lettering on a dark blue background.

Isle of Wight Glass logo added as a transfer to Renaissance cylinder vase

The Isle of Wight Glass logo here is on a Renaissance cylinder vase produced in 1989. Image courtesy of Kelv Gibbs.


Signatures

Signatures of the Harris family are shown below. More pictures are available on pages 137 and 138 of Mark Hill's book [1]. For signatures of other glass makers who worked at IOWSG please refer to the page for the Glassblower's Shelf.

Michael Harris

Signature of Michael Harris

Signature of Michael Harris on a Blue and White Swirls bell vase made in 1973.

Signature of Michael Harris

Signature of Michael Harris on an Azurene fish vase made c.1985-1987.

Signature of Michael Harris

Signature of Michael Harris on a Seascape bowl.

Signature of Michael Harris

Signature of Michael Harris on a 1970s globe paperweight.

Signature of Michael Harris

Signature of Michael Harris on a globe paperweight with 'England' added.

Jonathan Harris

Signature of Jonathan Harris

Jonathan Harris's signature on a Renaissance perfume bottle made in 1989.

Signature of Jonathan Harris

Jonathan Harris's signature on a Renaissance vase made in 1989. Note that the 'H' of 'Harris and 'E' of 'England are different from the signature above.

Signature of Jonathan Harris

Jonathan Harris's signature on a Nightscape perfume bottle made in the early 1990s.

Isle of Wight Glass in the hand of Jonathan Harris

This inscription was on an early experimental piece of graal made in 1989. It is in the hand of Jonathan Harris.

Signature of Jonathan Harris on early piece of graal

A signature with the studio written out in full on an early graal vase, thought to be made in 1992, but uncertain.

Timothy Harris

Signature of Timothy Harris early 1980s

This is one of the earliest signatures of Timothy Harris. It was on an experimental piece from the early 1980s. It is unusual in that it is signed "T Harris I.O.W.". Later signatures, it is believed, never abbreviate the first name.

Signature of Timothy Harris 1994

Timothy Harris's signature on a Charleston vase made in 1994.

Signature of Timothy Harris on piece made exclusively for Collectors Club members

Signature of Timothy Harris on a piece made exclusively for IOWSG Collector's Club members. The addition of the words 'Collectors Club' seems to be found only on the earliest club editions. This example is on the votive vase of Edition 2 in the Wild Garden style made in 2003.

Signature of Timothy Harris on piece made exclusively for Isle of Wight Glass Museum

Signature of Timothy Harris on a piece made exclusively for Isle of Wight Glass Museum. The inscription says "Timothy Harris IOW Glass for IOWGM 2016." The first piece with this signature was sold on 12th April 2016.

Other handwritten marks - Produced for Gregor

Produced for Gregor mark
Produced for Gregor mark
Produced for Gregor mark

The 'Produced for Gregor' mark has been seen on an Azurene 'Pink' flask perfume bottle, a Golden Peacock 'Royale' squat perfume bottle, and a Victorian 'Gold & White' squat perfume bottle. Perhaps this indicates the mark dates to around 1989, the only year the Victorian design was produced. Gregor was a Bavarian company that sold perfume bottles.


Advertising pieces and signs

IOWSG The Original sign, used 1996 to 2012

Isle of Wight Studio Glass 'The Original' sign, 9.3 x 9.3 cm. This logo was used 1996-2012. It is not certain when this little free-standing plastic sign was made.

IOWSG advertising block, 10 cm square

Advertising block, 10 cm square, with colours similar to Summer Fruits 'Mulberry' and a black transfer print. The block is hollow and not a solid piece of glass. There is a hole at the back. It was probably made after 2006.


IOWSG Hot Stuff pin badge

'Hot Stuff' pin badge, 37 mm in diameter.

IOWSG I Love Glass pin badges

'I Love Glass' pin badges, 37 mm in diameter. These were available from 2017.


Bibliography
1. Hill, M. (2006) Michael Harris : Mdina Glass & Isle of Wight Studio Glass. 158 pp. Mark Hill Publishing.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License