Posament Reconstructions

How to Determine Posament Knot Sizes

In order to make the spiral Birka posaments, the only truly necessary item is the spiral wire. The spiral wires from Birka are made of a very fine silver or gold wire with a round cross section wound around a silk core. An imperfect but adequate modern substitution for this is tenntråd, a silver/tin alloy round wire wound around a fiber core. It is often used in Sami-style bracelet weaving and comes in several sizes, denoted by the diameter of the constituent wire.

Wire diameter (mm) Spiral diameter (mm)
0.25 0.8
0.3 0.9
0.35 1
0.4 1.2
0.45 1.3
0.5 1.4
0.6 1.6

 

To determine the correct size of spiral wire to make the reconstructions, several steps were required. First, a gauge of all possible commercially available spiral wires was made. (All displays are presented within an 8″x10″ photo frame.)

CIMG6767

Then a swatch of each pattern was produced on the 0.25 spiral wire.

CIMG6766

Then, based on the % difference between the swatch exemplars and the extant examples and compared with the % difference between the gauge examples, an estimation of the correct spiral wire size was made.

Posament number Height of 0.25 exemplar (mm) Extant piece grave ID Height of extant piece (mm) Extant piece – loose or tight? % Change needed Reproduction tråd Height of reproduction (mm) % difference from extant Weight of reproduction (gm) Length of material (cm)
P1 2 798 2 tight 0% 0.25 2 100% 0.5 30
P2 6 798 4 tight -33% NA* NA NA NA NA
P3 2 886 2.5 tight 125% 0.3 2.5 100% 0.475 22
P9 5 643 7.5 loose 114% 0.25 7.75 103% 0.925 56
P10 6 520 7 tight 116% 0.3 7.75 111% 0.964 44.5
P11a 13 944 13 tight 0% 0.25 13 100% 0.985 59.5
P12 6 1040 8 tight 133% 0.35 8.25 103% 0.973 34
P13 6 944(?) 7.5 tight but spaced 125% 0.3 7.25 97% 0.864 39.5
P14 9 524 10 tight 111% 0.3 10.5 105% 1.469 67.5
P15 9 944(?) 12 tight 133% 0.3 11 92% 0.906 41.5
P17 6 561 8 loose 133% 0.35** 11 138% 0.507 17.5
P18 17 832 19 loose 111% 0.25 19 100% 1.347 81
P19 9 1125 19 loose 220% 0.5 20 105% 2.56 51
P20 11 520 15 loose 130% 0.35 16 107% 1.941 67.5
P21 8 524 14 loose 187% 0.45 14 100% 2.182 50
P22 12.5 524 17.5 loose 152% 0.35 17.5 100% 1.331 46.5
P23 3 561 8 tight 123% 0.35 8.75 109% 0.471 16.5
P24 5 327 11 tight 160% 0.4 11 100% 1.245 35
P26 4 989 5 tight 125% 0.35 5.5 110% 0.323 11.21

* P2 was not attempted because a finer tråd is needed than what is commercially available
** 0.35 is the only option available for gold plated
tråd

 

Finally, reconstructions in the appropriate size spiral wire were produced. (Note: P2 was not attempted, because an appropriately fine spiral wire was not available, P23 is slightly too large because the gold plated spiral wire was only available in 0.35 and 0.3 may have been closer, and P21 is the correct dimensions, but the spiral wire is coarser than the extant example.) While the commercially available tenntråd goes up to a size of 0.6mm, sizes of greater than 0.4mm are not recommended, as they are considerably
coarser than the extant posaments. While the spiral width of the extant
posaments vary, the wire diameter is usually much less than 0.25 mm.

CIMG6779

 

Recreations of an Example of Each Posament Knot

Please note that these are each based on a specific knot from a specific grave. The same knot in another grave may have very different dimensions. Likewise, different knots found in the same grave will not necessarily have the same gauge of tråd for all the knots! Exemplars are linked when there is an online image available. 

P1 – Based on an example from Grave 798 – 0.25 tråd

See Birka III for the exemplar.

Photo coming soon!

 

P2 – Based on an example from Grave 798

See Birka III for the exemplar

Not reproduced because currently available tråd is too thick

 

P3 – Based on an example from Grave 886 – 0.3 tråd

P3 with L scale

P3 crop

 

P9 – Based on an example from Grave 643 – 0.25 tråd

See Birka III for the exemplar

P9 with L scale

P9 crop

 

P10 – Based on an example from Grave 520 – 0.3 tråd

P10 with L scale

P10 crop

 

P11 – Based on an example from Grave 944 (11a) – 0.25 tråd

P11 with L scale

P11 crop

 

P12 – Based on an example from Grave 1040 – 0.35 tråd

Photo coming soon! 

 

P13 – Based on an example from Grave 944 – 0.3 tråd

P13 with L scale

P13 crop

 

P14 – Based on an example from Grave 524 – 0.3 tråd

Photo coming soon! 

 

P15 – based on an example from Grave 944 – 0.3 tråd

See Birka III for the exemplar

P15 with L scale

P15 crop

 

P17 – Based on an example from Grave 561 – 0.35 tråd*

* Please note that 0.3 tråd is probably the more appropriate size, but gold
plated tråd is only available as 0.35.

P17 with L scale

P17 crop

 

P18 – Based on an example from Grave 832 – 0.25 tråd

P18 with L scale

P18 crop

 

P19 – Based on an example from Grave 1125 – 0.5 tråd

See Birka III for the exemplar

P19 with L scale

P19 crop 2

 

 

P20 – Based on an example from Grave 520 – 0.35 tråd

P20 with L scale

P20 crop 2

 

P21 – Based on an example from Grave 524 – 0.45 tråd

     Please note that while the final SIZE is approximately accurate, the wire is far too coarse

P21 with L scale

P21 crop

 

P22 – Based on an example from Grave 524 – 0.35 tråd

P22 with L scale

P22 crop (2)

 

P23 – Based on an example from Grave 561 – 0.35 gold plated tråd

P2 with L scale

P23 top crop   P23 crop

 

P24 – Based on an example from Grave 327 – 0.4 tråd

P24 top with L scale

P24 crop   P24 top crop

 

P26 – Based on an example from Grave 989 – 0.35 tråd

P27 with L scale

P27 crop