The process flow of Nantong blue calico printing and dyeing techniques

Choose gray fabrics

Farmers usually choose high-quality cotton fabrics to dye blue printed fabrics; ordinary gray fabrics are mainly dyed in pure blue.

Degreasing

Soak the selected fabric in water containing additives such as Taikoo oil at a temperature between 50--60℃, then place the fabric in clean water and wait After 2-3 days, take it out and dry it for later use.

Paper mounting

The paper plate used for engraving is generally made of 3-5 layers of paper. The paper is made of 2-3 layers of Guiyang leather paper or mulberry paper, and 1-2 layers of Korean paper. Brush the frame with homemade flour paste, dry it and brush it with a layer of cooked tung oil, and then press it flat before use.

Painting and replacement

First use a wool-made brush (4-5cm in diameter), wrap one end tightly, and then use the brush with a little paint powder to replace the original Download or redesign a new sample.

Engraved pattern plate

Usually two to three layers of oil board paper (kraft paper) are stapled together, and the general pattern is drawn on the kraft paper, and a homemade carving knife is used to write the knife. When carving, the knife must be vertical when carving, and the upper and lower flower shapes should be consistent. After cutting the bevel with an iron sheet, it is clamped and wrapped with bamboo slices. There are three types of carving knives: single slanted knives, double knives, and round-blade knives made from iron sheets (commonly known as blunderbuss). Single-knife faceting is the main method, and the lines carved with double-knives are narrow and consistent in width. There are several types of bludgeons, large and small, and they are mainly used to hit the dots required for pattern making.

There are techniques for engraving such as facets, lines, and dots. Facets mainly use the cutting method of a broken knife to express large patterns. This is also the most typical cutting method in blue calico. , the carved lines should be carved smoothly and smoothly. The lines in the blue calico pattern are divided into negative lines and positive lines. The dots are usually pounded with a homemade tool, and the dots generally play a decorative role in the pattern. In addition to engraving, there are also replacement plates. The patterns used in the early stages are retained by painting and then engraving, so that they can be used repeatedly.

Apply tung oil

First use pebbles to smooth the back of the carved pattern, then brush with cooked tung oil to reinforce it, dry it, and brush the front and back with oil 2-3 times, and finally Dry and flatten, store in categories, and print the dye paste directly when needed.

Squeegee

Before squeegeeing, sprinkle water on the gray cloth and then roll the cloth. Moistening is to allow the white cloth to better absorb the dye paste. Corn flour, wheat flour, glutinous rice flour, etc. have been used in the anti-dye slurry of folk blue flower cloth. After several generations of exploration and practice, soybean flour with moderate viscosity was finally selected. However, simple soybean flour is easy to deteriorate in summer and has high cost. After adding lime powder, it is not only easy to scrape the sizing, but also easy to scrape off the mortar after dyeing. Therefore, people still use soybean powder and lime to make anti-stain slurry. The ratio is 1:0.7, and water is added to make a paste. Sometimes glutinous rice flour and lime are also used as anti-dye paste according to the requirements of the pattern. When mixing the slurry, the thickness (viscosity) should be moderate. The finer the soybean flour and the more transparent the slurry is, the better the viscosity will be.

Put the carved pattern on the white cloth and then scrape it. Use even force when scraping. Scrapers are generally made of forged iron in Jiangsu and Zhejiang areas, with wooden round handles. They are also made of horns and wooden boards in Hunan and Hubei. It is more important to connect the pattern when scraping. When the pattern is complex, the pattern alignment must be accurate and the typesetting must be free. Then the gray fabric with anti-stain paste needs two days to dry in the shade. After the mortar is dry, it is put into the vat for dyeing.

Dyeing

Pour the indigo into a small vat, mix 5 pounds of indigo with 8 pounds of lime, 10 pounds of rice wine and an appropriate amount of water, so that the indigo water turns yellow and indigo foam forms on the water. Commonly known as indigo flower among the people, it can be poured into a large vat for dyeing. Before dyeing, put the bamboo basket in the middle of the vat to prevent the dyed cloth from sinking to the bottom of the vat and causing vat feet to appear, which would affect the dyeing. Then loosen the sizing cloth and soak it in water until the cloth is soaked until the sizing becomes soft, then it can be dyed in the vat. After placing the cloth in the vat for 20 minutes, take it out for oxidation and ventilate it for 30 minutes, and continuously rotate the cloth surface to make it oxidize evenly. The time for placing the cloth in the vat and oxidation can be adjusted according to the different fabrics and climate changes.

The blue of blue calico is pure because of the use of plant dye - blue grass. According to "Guangxu Tongzhou Chronicles": Sow indigo to form a border, mow the first indigo in May, and mow the second indigo in July. Pour a pool of water, soak the water in lime, stir it for a thousand times, drain the water, and it becomes indigo. . Used for dyeing cloth, it is called Xiaotanqing.

Those who come from Rugao are especially good at names. After sowing in spring and harvesting in autumn, the leaves are soaked in a stone pond. After a few days, the rotten branches are removed and lime or sea clam powder is added to allow them to settle. The precipitated dye looks like earth and is commonly known as soil indigo.

On May 7th every year, Nantong people harvest the local bluegrass and process it as dyeing pigment for blue calico. In the Ming Dynasty, indigo was a tribute to the imperial court. It gave the blue calico a pure and solemn undertone. Plant dyes are specially formulated to produce dye vat water for printing and dyeing blue calico. Each dye vat is as tall as a person. It contains living water that has not died for thousands of years. The printed white cloth and the cloth painted with mortar are put into the dye vat. Microorganisms are constantly in the dye vat. The movement in the water dyes the parts without mortar blue, while the parts stained with gray retain their original white color.

Careful maintenance of the dye vat is a unique skill passed down from ancestors and is not passed down to outsiders. In order to keep the secret, the dye vat people always adjust their formula in time after carefully checking the water in the dye vat every night. Every morning before dyeing cloth, the master will check whether the dyeing water in the big vat is mature, scoop up the seedling water in the vat with a bowl, first rub it on the head with the index finger, and then put it next to the bowl after the finger is stained with grease. Look at the size of the color on the water of the seedlings. If the water surface in a bowl is pushed away quickly, the indigo water in the vat will have a larger color. On the contrary, the water in the vat must be adjusted by gray wine and mature before it can be dyed. The dye vat water is the life source of blue calico, and the dye vat man is also a respected artist in the dyeing workshop.

Scrape off the dust

After the dyed cloth is dried, scrape off the dust and scrape off the anti-dye paste after dyeing. After the cloth is dried out of the vat, it will be heavier in ash and alkali. It needs acid to fix the color. After cleaning, stretch the cloth on the stand and use a custom scraper with round ends or a household kitchen knife tilted at 45° to scrape off the mortar with moderate force. Be especially careful not to scratch the cotton cloth when scraping. The dyed cloth has removed the shallow mortar, revealing the true color of the seal. Where the mortar blocks are large, the gray layer naturally cracks during the rolling of dyeing, and the indigo penetrates into the gray fabric along with the cracks, leaving a natural texture that cannot be described artificially. Natural texture is the soul of blue calico art.

Cleaning and drying

After scraping the cloth, it needs to be cleaned 2-3 times. Clean the remaining mortar and floating color on the cloth surface and dry it. Due to the influence of process factors such as scraping, dyeing, and drying, the length of blue printed cloth is generally limited to less than 12 meters. The dyeing master uses a long bamboo pole to lift the wet cloth onto a 7-meter-high drying rack. The scene when drying is very spectacular. . Finally, use a rolling stone to roll the cloth flat.

The dyed cloth is dark blue. After drying, it gives people a sense of earthiness and solidity, so some people call it old blue cloth. After dyeing, the shallow floating mortar is scraped off, revealing the true color of the sealed areas with mortar. Where the mortar is large, the gray layer will naturally crack during the rolling of dyeing, and the indigo will penetrate into the gray fabric along with the gaps, leaving artificial traces. Indescribable natural ice patterns. Even if they are made by the same artist, the printed patterns are different and show great variety. The superb skills of folk artists and the unique artistic style of blue calico are praised by people.