Dating Orrefors Slip Graal (or Slipgraal) Glass pieces
The Slip Graal (or Slipgraal) technique was invented in the late 1930s. Slipgraal pieces did not have their own numbering system until about 1940. Until then, they were signed like the Graal pieces. Since then, the letter “S” is added (generally) in front of the serial number in order to designate the Slip Graal technique. From 1950 onward the serial number / date code had a letter added to it. The signature therefore usually consist of 4 parts:
1. The name “Orrefors”, sometimes with “Sweden” or “Suède” added.
2.The technique used: “S. Graal” or “Graal S.” for Slipgraal or Slip Graal
3. The serial number / date code.
4. The name of the designer.
In 1956 Edvard Hald, together with Heinz Richter, experimented with different methods for the manufacture of Slip Graal pieces and came up with a technique called Aquagraal (on some pieces it is erroneously written Auqua-Graal). The basic difference is that they first used a solvent, and later poreclain paint, which they applied to the glass in order to “draw” the design. The solvent or the paint would burn up when the glass was reheated and air would be trapped to shape the design. The Aquagraal pieces did not have a seperate numbering system then Slip Graal pieces. The only difference is that they are marked Orrefors Aquagraal or Orrefors Aqua Graal rather then Orrefos Slip Graal.
In the table below you can see the the different serial numbers / date codes that were used from 1940 until 1982 on Orrefors slipgraal pieces:
1940 – S. 21 to S. 64
1941 – S. 65 to S. 183
1942 – S.184 to S. 204
1943 – S.205 to S. 278
1944 – S.279 to S. 415
1945 – S.416 to S. 634
1946 – S.635 to S. 688
1947 – S.689 to S.926
1948 – S.927 to S.1276
1949 – S.1277 to S.1689
1950 – S.51 B to 52 B and S.53 L to 399 L
1951 – S.400 L to S.847 L
1952 – S.848 L to S.1175 L
1953 – S.1176 L to 1600 L
1954 – 1601 L to 2308 L
1955 – 2309 L to 2310 L and 50 M to 433 M
1956 – 100 N to 289 N
1957 – 51 O to 225 O
1958 – 226 O to 344 O
1959 – 345 P to 440 P
1960 – 441 P to 558 P
1961 – 559 R to 573 R
1962 – 574 S to 585 S
1963 – 586 T to 619 T
1964 – 620 V to 638 V
1965 – 639 A to 650 A
1966 – none manufactured this year
1967 – none manufactured this year
1968 – 651 C to 664 C
1969 – 665 D to 722 D
1970 – 723 E to 737 E
1971 – 738 F to 813 F
1972 – 814 G to 854 G
1973 – 855 E3 to 1320 E3
1974 – 1321 E4 to 1796 E4
1975 – 1797 E5 to 1960 E5
1976 – 1961 E6 to 2111 E6
1977 – 2112 E7 to 2281 E7
1978 – 2282 E8 to 2448 E8
1979 – 2449 E9 to 2558 E9
1980 – 2559 80 to 2566-80 and 2567 F1 to 2639 F1
1981 – 2640 F2 to 2790 F2
1982 – Only Gallery Pieces