Fibre Selection: Cotton, Flax, and Rush

The choice of wick fibre determined how a candle burned — how quickly the wax was drawn up, how much the flame guttered in a draught, and how much residue was left as the candle consumed itself. Italian candle makers working before industrialisation had access to several fibre types depending on their region.

Cotton was the dominant material in central and northern Italy by the late medieval period. Its absorbency and relative softness made it suitable for both beeswax and tallow candles. Flax — used in the same regions for linen production — appeared as a wick material where cotton was scarce or expensive, though its higher density required more careful sizing to match the wax's viscosity.

Rush wicks, made from the inner pith of the common rush (Juncus effusus), were documented in poorer domestic lighting. The pith was stripped from the outer skin, leaving a white, soft core that could be quickly prepared and used without braiding — simply dipped repeatedly in tallow. These rush lights were the cheapest available form of indoor illumination and are documented in household accounts from rural areas of Tuscany, Umbria, and Lazio through the eighteenth century.

Hemp appeared occasionally in coarser candles and torches intended for outdoor use, where burn duration and robustness in weather mattered more than flame quality. Its rougher texture and tendency to produce a larger, less controlled flame made it unsuitable for altar or decorative candles.

Cleaning and Initial Preparation

Raw cotton or flax fibres arrived in the candle workshop in unspun or minimally processed form. Before use, fibres were cleaned of seed residue, dust, and foreign material by hand-combing or carding with a simple toothed board. This produced a more uniform sliver — a loose, continuous bundle of parallel fibres — from which thread could be drawn.

The degree of cleaning affected burn quality. Inconsistencies in fibre density along the wick length produced uneven burning: sections of higher density burned more slowly, creating a widening pool of liquid wax that could spill or drown the flame. Careful preparation reduced these inconsistencies and was one of the principal skills distinguishing an experienced wick maker from a novice.

After initial cleaning, the fibres were sometimes soaked briefly in water to soften them before twisting — a step that helped the fibres align and bind to each other without breaking. Excessive moisture was then removed by pressing and air-drying before any heat treatment was applied.

Chemical Treatment: Saltpetre and Borax Solutions

Untreated cotton or flax wicks, when extinguished, often continued to glow or smoulder — a phenomenon called afterglow — and produced a curled, carbonised tip that could fall as a spark or clog the base of a candle holder. To reduce afterglow and improve burn behaviour, Italian candle makers developed treatment baths based on materials available through apothecary and agricultural supply networks.

The most consistently documented treatment used a dilute solution of potassium nitrate — saltpetre (salnitro) — in which prepared wick lengths were soaked for several hours and then dried. Saltpetre alters the combustion chemistry of the fibre, causing it to ash cleanly without afterglow and without excessive charring. Its use in Umbrian monastery candle rooms is recorded as early as the fifteenth century, and it remained the standard treatment in traditional Italian candle workshops through the nineteenth.

Borax solutions appeared in later workshop records, particularly in urban northern Italian production, as a slightly less reactive alternative to saltpetre. Borax produced a similar ash-and-extinguish effect on the wick tip and was available in increasing quantities as trade with Central Asian supply regions expanded through Venice and Genoa.

Lime water — a dilute calcium hydroxide solution — is mentioned in several regional craft accounts as a third option, used particularly where saltpetre was expensive or difficult to obtain. Its effectiveness was regarded as inferior to the saltpetre treatment in contemporary sources that compared the two methods.

Twisting and Braiding Techniques

Once fibres were prepared and treated, they were formed into the finished wick through twisting or braiding. The distinction between a twisted and a braided wick has consequences for burn behaviour that Italian candle makers understood empirically well before the underlying chemistry was formalised.

A twisted wick — made by rolling prepared fibre bundles between the palms or against a flat surface to create a uniform cord — burns in a relatively straight column. Its principal disadvantage is that it does not curl as it consumes, meaning the carbonised tip must be trimmed by hand during use (the act of snuffing or trimming a candle) to prevent a large, smoking flame. Twisted wicks are documented as the older technique and remained in use for coarser candles and torches where flame management was less critical.

A braided wick — formed by interweaving three or more fibre bundles in a flat or round plait — curves as it burns because the interweaving introduces a slight asymmetry. This natural curl carries the wick tip into the hottest zone of the flame, where it is consumed cleanly without trimming. The flat three-strand braid, documented in Tuscan workshop records from the sixteenth century onward, was the dominant form for quality wax candles by the early modern period.

In Umbrian monastery records, a specific braiding pattern described as a treccia a tre fili (three-thread plait) is mentioned in connection with beeswax altar candles. The tightness of the braid — controlled by the tension applied during plaiting — determined the wick's capillary action: a looser braid allowed faster wax draw-up and a larger flame; a tighter braid slowed draw-up and produced a smaller, steadier flame suited to enclosed spaces and prolonged liturgical use.

Sizing the Wick to the Wax

The relationship between wick gauge and wax viscosity is one of the less explicitly documented but clearly understood aspects of traditional Italian candle craft. A wick that is too thin for the volume of melting wax produces a pool that drowns the flame; a wick that is too thick draws wax too rapidly, producing a large, irregular flame with excess smoke.

In practice, Italian candle makers calibrated wick gauge to candle diameter and wax type through accumulated experience rather than written tables. Workshop accounts occasionally note wick weights per unit length as an indirect measure of gauge, and the consistent production of specific candle sizes within a workshop over generations implied a stable wick specification maintained by practice rather than formal record.

Beeswax, with its higher melting point and lower viscosity at working temperatures, required a relatively fine wick compared to tallow. Paraffin, introduced later, melts at lower temperatures and has higher viscosity at working temperatures, requiring a thicker or more loosely braided wick — a distinction that caused problems for traditional workshops transitioning to paraffin blends without adjusting their wick specifications.

Regional Variation and Geographic Patterns

The evidence available from workshop records, guild regulations, and ethnographic accounts suggests clear regional variation in wick preparation across Italy, though the patterns are not always consistent or well-documented.

Central Italian workshops — particularly in Umbria and Tuscany — show a strong preference for the flat three-strand cotton braid with saltpetre treatment, matched to beeswax candles of moderate size. Northern Italian urban workshops, particularly in the Veneto, show earlier adoption of borax treatment and a somewhat broader range of fibre choices, possibly reflecting their access to Mediterranean and Adriatic trade goods.

Southern Italian documentation is sparser. What exists suggests a higher persistence of twisted rather than braided wicks in rural areas of Campania and Sicily, possibly reflecting both the dominance of olive-based and tallow materials (which tolerated twisted wicks better) and slower diffusion of the braiding techniques from urban northern centres.

Sources and Further Reading