 |  | Dyeing of Leaves and Straws: A Handbook for Craft Instructors (NRI) | ||
 |  | Raw materials | ||
|  | Iraca straw and jippi-jappa | ||
| | Big thatch, cabbage palm and Puerto Rican hat palm | ||
| | Silver thatch | ||
| | Pandanus ('screw pine') | ||
| | Vetiver grass | ||
| | Coconut leaves | ||
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Source and areas of production
The toquilla palm (Carludovica palmate) is the source of the iraca straw used in Colombia to make 'Panama hats' and handicrafts. The straw is also called 'Paja de toquilla' or 'jipi japa'. The toquilla palm has no true stem, the leaves growing from the ground on long petioles which may attain a length of 3 m. Most of the straw is obtained from wild plants. However, the plant grows well on banana plantations in the shade of the banana plants. In Jamaica the 'jippi-jappa' plant (C. jamaiciensis) yields a straw which is used for similar purposes. These palms belong to the Cyclanthaceae or 'screw pine' family.
The toquilla palm is found in an area stretching from Guatemala and Honduras in Central America to Ecuador, Peru and Colombia in South America. It also grows east of the Andes in Venezuela and in Guyana and has been introduced into Puerto Rico and the Philippines (du Frane, 1945). C. jamaiciensis has been introduced into Singapore.
Extraction and processing of iraca straw
The straw is extracted from the young unexpanded leaf which is about 1 m long. The leaf is made up of four divisions, each of which is then divided into six or seven segments or bands. The leaf is 'ripped' with a comb-like tool and the mid-ribs removed, leaving the straw strips which are later used for weaving. Although most of the leaf is ripped, the base is untouched so as to keep the strips together for easy handling. Bunches of strips are boiled for 2 hours in a large pot, after which they are hung in the shade during the middle of the day until they are dry. Once dry they are laid upon the ground in the sun for 3 days. The bunches are then placed in chambers where for about 12 hours they are exposed to the fumes from burning sulphur. The bleaching action of the sulphur dioxide produced is more effective if the leaves have been dampened first. The quality of the straw depends on the combined effects of the sun and sulphur treatment.
Extraction and processing of jippi-jappa
The extraction and processing of jippi-jappa is basically similar to iraca straw (Spence, 1964) but differs in the following respects:
(i) Drying is carried out in the bright sun - it takes 2 days.
(ii) The straws are damped after drying and then placed on a clean dry surface to dry.
(iii) Before bleaching, the articles are washed in soapy water, rinsed and partially dried.
(iv) Bleaching, carried out in a box or a barrel, takes 15 minutes.
Suitable classes of dye
Basic and disperse dyes are, apart from a very few acid dyes, the only ones which can be used with these materials. Some of the shades obtained are quite durable although light fastness is always lower than on other materials and the build up of shade varies greatly from batch to batch (see Tables 1(a), 2(a) and 3(a)).
Source and areas of production
The palm Sabal jamaiciencis, which is known in Jamaica as 'big thatch', comes from a genus of palms known as 'fan palms'. Although a native of the warmer parts of North and South America the genus has been introduced elsewhere. The 'Sabal palm' or 'cabbage palm' (Sabal palmetto), so called because of its edible bud, yields the palmetto fibre which is used as a brush filling. The best quality brush fibre is obtained from the young leaf stems. The leaves are also used in making hats, mats, baskets and various novelties for the tourist trade.
S. causiarum is known in Puerto Rico as the 'yaray'. It is also known as the 'Puerto Rican hat palm'. The shiny green curved leaves attain a length of 1 m or more and are borne on a smooth trunk 3 - 5 m high. The palm grows in abundance in sandy soils on the west coast of Puerto Rico and the east coast of the Dominican Republic.
Extraction and processing of big thatch
The extraction and processing of big thatch has been described by Spence (1964). Alternate heart leaves are cut whilst they are still sword-shaped. One leaf is always left on the plant. The sword is 'fermented' or 'cured' by being kept indoors and away from direct heat. Complete curing takes about 4 days under normal conditions (for quick curing, the sword is put to dry in the sun, either in a hanging position or on a flat hard surface and turned occasionally). If the thatch becomes brittle it is put in the dew for an hour or more. While working it is kept cool and moist by wrapping the strips in a lightly damped cloth or newspaper. Skeining or removal of the ribs is carried out using a small pointed knife. The knife is run from the base to the tip of the leaf and the ribs are stripped off. During the skeining all strips are produced at a uniform width. The blades or leaflets are split into strips with the finger nails. The tops and bottoms are cut off giving a length of 50 cm. The more pliable strips are selected for plaiting.
Processing of Puerto Rican hat palm
Only young unfolded leaves are collected. They are dipped in boiling water and dried in the sun. The thin, tough segments of the leaves are split into narrow strips and these are woven into hats, mats, baskets and many useful and fancy articles. Since the strips are flat and rather firm in texture they are not woven so closely as to prevent ventilation. The finer quality hats are woven in the morning and evening or in rainy weather, but the cheaper hats may be woven at any time (Dewey, 1943).
Suitable classes of dye
Basic, acid and disperse dyes will produce durable shades (see Tables 1(b), 2(b) and 3(b)). Intense colours are best obtained using acid dyes.
Sources and areas of production
The source of the material used in Jamaica for plaiting into ribbons which will be made up into baskets, etc., is the palm Cocothrinex fragrans which much resembles C. argentea but has yellow fragrant flowers. C. argentea has leaflets which are dull green above and silvery beneath. The trunk grows to a height of 9 m (McCurragh, 1960).
Extraction and processing
The material is extracted and processed in a similar way to big thatch.
Suitable classes of dye
The straw behaves in a similar way to big thatch (see above); however, since the differences between the upper and lower surfaces cannot be concealed, it is best to use them for effect.
Source and areas of production
Pandanus tectorius (P. odoratissimus) the 'textile screwpine' is common in the tidal forests of South-East Asia and Polynesia. The leaves are used for making mats, baskets, hats and other craft goods (Morton, 1976). The tree is extensively branched and grows to a height of about 5 m. Several races have been selected for cultivation from the wild plant, which is var. Iittoralis. Among these are the races without thorns cultivated in gardens, which collectively make var. Iaevis (Burkill, 1935). Varieties of pandanus are found also in the Caribbean and are used in handicrafts in Dominica, Grenada and Jamaica. In the Philippines pandanus is widely used for hats and matting. The very strong and durable 'sabutan hats' are made from the young leaves while they are still green.
Extraction and processing
For making matting in Malaysia, the leaves are cut and allowed to dry slightly over a fire before being split into two down their length by removing the spiny mid-rib. The halves are then cut into strips - the Malays do this by dragging them over a board with brass spikes in it - and the prickly edges are thrown away. Elsewhere the prickly edges may be removed with the mid-rib. The strips are then pulled over a bamboo and beaten with a pestle to improve their suppleness (Burkill, 1935). After soaking for 3 days in changes of water, and bleaching in the sun, the strips are ready for weaving into baskets, etc.
In Grenada, craft straws are obtained by first boiling the green leaves for about 30 minutes and then bleaching them in the sun. To do this, the wet leaves are spread out in direct sunlight but not allowed to dry. When the green colour has been discharged the damp leaves are rolled end-to-end to prevent them shrivelling during the final stage of drying. The coiled leaves are allowed to dry naturally in the shade and are finally split into strips of useful width.
Suitable classes of dye
Pandanus leaves can be dyed with selected acid, basic and disperse dyes. Few dyes give colours of good light and water fastness. However, with careful selection the fastness properties will be adequate for many purposes (see Tables 1(c), 2(c) and 3(c)).
Basic, disperse and 1:2 metal complex acid dyes (e.g. Bayer 'Isolan' dyes) give the most uniform colours.
Sources and areas of production
The small genus Vetiveria of the grass family Graminae is found in the tropics of Africa and Asia. Two species are very common: Vetiveria nigritana, which is found in Africa where its tough leaves are used for thatching; and V. zizanoides, which is found in Asia (Burkill, 1935). V. zizanoides is cultivated mainly for its root which, on distillation, yields an oil used in perfumery. The plant is also grown as a soil binder to prevent coastal erosion. The dried grass is used for making brooms as well as thatching roofs (Council of Scientific and Industrial Research, 1976). In Dominica the production of verti-vert (vetiver) straw plaits and mats provides a valuable source of employment for girls in the rural areas.
Processing
Apart from being laid out in the sun to dry, the material is not processed. The resulting pastel green colour can be lightened using a method similar to that used for pandanus in Grenada; however, the treatment may have to be repeated.
Suitable classes of dye
The pale green straw is readily coloured with selected acid and basic dyes; however, the natural green colour of the straw must first be discharged, e.g. by sun bleaching, if clear uniform colours of the best possible light fastness are required. Although none have been used on this material it would be worthwhile trying disperse dyes.
Of the dyes evaluated, the 1:2 metal complex dyes (e.g. Bayer 'Isolan' dyes) appear to be the best choice but some selected ordinary acid dyes also look promising. In general, the basic dyes produce colours with better water fastness than those from ordinary acid dyes but the colours tend to be weak and the light fastness tends to be low (see Tables 1(d) and 2(d)).
Source and areas of production
A useful craft straw can be obtained from the leaves of the coconut palm (Cocos nucifera) which is the most important of all the cultivated palms and is widely distributed throughout the tropics.
Extraction and processing
In some countries the straw is prepared by first boiling the fresh leaves and separating the two faces of each leaf which are then split into strips of convenient width and boiled for 1 - 2 hours in a 5 - 8 per cent solution of soda ash (sodium carbonate). The strips are chemically bleached (for 1 - 3 days), washed and finally dried in the shade. This treatment yields a smooth semitransparent raffia-like material which is said to be strong, elastic, light and similar in quality to iraca straw.
Suitable classes of dye
Limited dyeing trials on the material gave promising results when using acid, basic, disperse and direct dyes (see Table 4). In addition to the dyes listed, dyers should also experiment using dyes which give good fastness properties on other materials evaluated (see Tables 1 - 3). Methods of applying direct dyes have been described by Canning and Jarman (1983).
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