Vertical vs. Horizontal Looms

I spend a lot of my time talking to people about weaving and this sometimes leads to discussions of looms. Most people are familiar with warp-weighted looms, but what other types of looms were used in the Middle Ages? Where and how were they developed? These types of looms are categorized as vertical or horizontal looms. The evidence is found for two styles of vertical looms, the warp-weighted loom, and the vertical two-beamed loom. There is also evidence for three styles of the horizontal loom: the heddle rod horizontal loom, the treadle horizontal loom, and the drawloom. This article will briefly summarize the types of looms and their proposed development throughout different cultures and time periods of the Middle Ages.
Warp-weighted looms seem synonymous with the Middle Ages, probably because they are different to what we use now. I assume anyone reading this article is familiar with warp-weighted looms and the evidence for them. There is also very good evidence from drawings which indicated that Egyptian weavers used a vertical two-beam loom from as early as 1552 BCE (Geijer, 1979). Well before the Middles Ages, in 1786 BCE a two-beam horizontal loom was also in use in Egypt (Geijer, 1979; Harris, 1995). This loom included a heddle rod ( the same as a warp-weighted loom). Later horizontal looms see the additional of treadles, so the shafts can be controlled by the weaver's feet rather than hands, or other people (Geijer, 1979). Geijer (1979) also noted that the drawloom was available to Persian weavers as early as Sassanid times (3rd-7th C AD).
 Roman weavers are also believed to have developed a horizontal loom which utilized heddle rods. Walton et al (2001) determined from the Roman damask twills that such a loom was likely used to create damask twill as early as the 3rd Century AD. These damask twills would be far easier to achieve on a horizontal loom with heddle rods, than a vertical loom, due to the number of rods that would have been in use. At least 8 rods would need to be used to achieve the damask twills found in Roman dig sites (Walton et al, 2001; note Roman damask is really a block twill and does not require a drawloom. It is far easier to allow this number of heddle rods to rest on a horizontal warp than to devise a mechanism that would hold them on a vertical loom (Walton et al, 2001). Due to the errors which occur throughout some of these textiles, it is believed that heddle rods were used rather than treadles.
The treadle loom was first likely developed in Han Period. Based on drawing from this period textile historians believe this loom was body tensioned with a natural shed and pedal that lifted a heddle rod shed, to create the second shed, figure on pg 34 (Geijer, 1979). Geijer (1979) wrote that these looms were likely no wider than 50 cm (19.5”), as this was the maximum width, according to government documents, allowed in the workshops.  Han weavers were initially only weaving plain weave, Han fabrics were highly regulated and used to pay taxes, woven widths varied from 20-50 cm (Geijer, 1979). 
Geijer (1979) proposed that the Sasanids developed the treadle loom when they had access to silk thread. Becker (1987) proposed one possible progression from heddle rods to drawloom technology as follows; pattern rods within the warp, pattern heddle rods, pattern shafts, a harness drawloom, and individually weighted harness cords, and finally a drawloom with a comber board. Becker (1987), Geijer (1979), and Hoskins (1992) noted the difficulties in exactly dating the development of the drawloom. All theories have been based on textile analysis and looms are primarily made of wood, which had long since decomposed by the time modern excavations were conducted. It is commonly believed that Middle Eastern and Chinese drawlooms required the use of a drawboy, a young boy who sat on top of the loom and pulled the cords to create the design (Becker, 1987; Geijer, 1979). Becker (1987) referred to the European drawloom as the precursor to the modern drawloom with comber board. Becker (1987) does not specifically state the use of a comber board before the 18th Century and therefore a definitive statement about the use of a comber board will not be made in this paper.
The treadle loom arrived in the north-west Alps around the 11th C, mainly the Netherlands and Belgium (Geijer, 1979). Geijer proposed the move from vertical loom using heddle rods, which were changed with hands, to heddle rods connected to treadles which are changed by foot. When this change happened in Europe it meant weaving moved from domestic craft to structured profession and therefore weaving transferred from women to men (Geijer, 1979)) This change also effects fabric which went from smaller rectangular pieces to production lengths of cloth (Geijer, 1979). Initially, only 2 heddle rods were available, so only plain weave possible. Geijer noted that no beater was evident in drawings which have survived (Geijer). Evidence from the 12th C showed that looms were adapted for 4 end twills and two weavers “broadcloth” (Geijer). 
The loom depictions from this time which appear in 1363 clothmakers guild regulations from Ypres. (Geijer) At this time the Flemish woolen industry flourished (Geijer). Geijer noted that finds from the Crusader Era (1000-1200) require further research into the transmission of the treadle loom from the Low Countries to Scandinavian countries. The finds along the Baltic show coarse weavings using 3 end twill, which she stated was uncharacteristic of a warp-weighted loom. However, Wild (b, 2003) attributed weaves such as these to European weavers but made no suggestion of which type of loom was used.
In summary, the style of loom used by those seeking to recreate historical textiles should be informed by the time period and culture they are recreating. For a pre-11th C European weaver, the warp-weighted loom would be the best assumption. For weavers from the Middle and Near East, such as my 7th C. Sasanian persona, a vertical two beamed loom is the best choice for weaving taquete, tapestry roundels, or other tapestry decorations. However, a horizontal treadle drawloom is the best choice for standard fabric. The drawloom is necessary for reproducing damask fabrics of the age and likely the loom of choice for samitum cloth.
Works Cited
Becker, John. (1987). Pattern and Loom. Rhodos International Publishers, Copenhagen.
Geijer, Agnes (1979). A History of Textile Art. W.S. Maney & Son Ltd. Leeds.
Harris, Jennifer (1995). 5000 Years of Textiles. British Museum Press. London.
Hoskins, N.A. (2004), The Coptic Tapestry Albums & the Archaeologist of Antinoe, Albert Gayet. Skein Publications in Association with University of Washington Press. Seattle and London.
Hoskins, N.A. (1992). Weft-Faced Pattern Weaves: Tabby to Taquete. University of Washington Press. 
Rogers, Penelope Walton. (2007) Cloth and Clothing in Early Anglo-Saxon England. Council for British Archeology. York
Rogers, Penelope Walton. et al (2001) The Roman Textile Industry and it's Influence. A Birthday Tribute to John Peter Wild. Oxbow Books. Exeter
Wild, J.P. a (2003) Later Roman and early Byzantine East (300-1000 AD). In Jenkins, D. The Cambridge History of Western Textiles. (Pages 140-152). Cambridge: University of Cambridge.
Wild, J.P. b (2003) The Romans in the West (600 BC-400 AD). In Jenkins, D. The Cambridge History of Western Textiles. (Pages 77-117). Cambridge: University of Cambridge.
Wild, J.P. c (2003) Textiles in Archeology. CIT Printing Services, Ltd. Pembrokeshire.