You might find this to be relatively uninteresting but we hope that you'll read it anyway because it truly is fascinating how many ways there are to print fabrics. Do not confuse this with "DYING" fabric because that would imply that the whole piece of cloth is uniform whereas "PRINTING" textiles uses only certain colors in certain areas with sharp lines. Let's begin the fascinating journey of TEXTILE TECHNIQUES!
Starting with something very basic, starch, we all know what it is and we've all used it at some point whether for ironing clothes to keep them crisp or used in the kitchen for a thickener. Starch is a very versatile commodity and sometimes we take advantage of it and ignore the possibilities for it, it can be used for so much more than the basics that we know about. We're going to prove it with this textile technique of STARCH PRINTING for fabrics.
Starch is a carbohydrate (sometimes known as amylum) and it has a large number of glucose molecules joined together by glycosidic bonds. This is all scientific stuff but you'll need to know that it's produced by most green plants as an energy store so starch is readily available. You'll find starch in potatoes, wheat, maize, rice, and cassava. Starch itself is insoluble in cold water or alcohol but when you add it to warm water, it makes a wheat paste, so we'll delve right into the idea for using starch powder as a printing agent. Once you add cold water and starch you get a wheat paste (you know this already) but add some olive oil then boil it to make it thick, this will allow you to form a pattern on a piece of fabric before printing on it so that when the colors take to the fabric, the starch paste will leave that section untouched. However acidic or very alkaline colors will seep through the starch so it's important to know which colors are alkaline and acidic.
With those colors there are problems with the design being rendered useless if you want to use those specific colors and when you a make a paste it thickens up to a stiff unworkable jelly. In the case of those unusable colors, while mineral acids or acid salts convert it into dextrine, thus diminishing its viscosity (thickening power), organic acids do not have that effect. Today, modified carboxymethylated cold soluble starches are mainly used. These have a stable viscosity and are easy to rinse out of the fabric and give reproducible "short" paste rheology (soft solid state). Flour paste is made in a similar way to starch paste; it's sometimes used to thicken aluminum and iron mordants. Starch paste created from rice flour have been used for several centuries in Japan and is still used today as a starch printing technique on fabrics.
The way this technique works is that you take the paste and put it on the fabric in which you don't want any dye to adhere to such as calico prints. If you want an indigo dyed shirt with white dots then you'll put that paste into small dots all over the fabric. When the fabric get submerged into the dye, the starch will prevent it from becoming blue. The end result is the starch will brush off after it dries, leaving white dots all over the fabric. Over time these dots will fade away whereas discharge printing (we'll talk about that later) will stay no matter how many times you wash/wear it. The only way to differentiate between starch and discharge printing is to look on the underside of the fabric, if you see the pattern leaked through then that's discharge printing but if you don't see it then it's starch printing.
Starting with something very basic, starch, we all know what it is and we've all used it at some point whether for ironing clothes to keep them crisp or used in the kitchen for a thickener. Starch is a very versatile commodity and sometimes we take advantage of it and ignore the possibilities for it, it can be used for so much more than the basics that we know about. We're going to prove it with this textile technique of STARCH PRINTING for fabrics.
Starch is a carbohydrate (sometimes known as amylum) and it has a large number of glucose molecules joined together by glycosidic bonds. This is all scientific stuff but you'll need to know that it's produced by most green plants as an energy store so starch is readily available. You'll find starch in potatoes, wheat, maize, rice, and cassava. Starch itself is insoluble in cold water or alcohol but when you add it to warm water, it makes a wheat paste, so we'll delve right into the idea for using starch powder as a printing agent. Once you add cold water and starch you get a wheat paste (you know this already) but add some olive oil then boil it to make it thick, this will allow you to form a pattern on a piece of fabric before printing on it so that when the colors take to the fabric, the starch paste will leave that section untouched. However acidic or very alkaline colors will seep through the starch so it's important to know which colors are alkaline and acidic.
With those colors there are problems with the design being rendered useless if you want to use those specific colors and when you a make a paste it thickens up to a stiff unworkable jelly. In the case of those unusable colors, while mineral acids or acid salts convert it into dextrine, thus diminishing its viscosity (thickening power), organic acids do not have that effect. Today, modified carboxymethylated cold soluble starches are mainly used. These have a stable viscosity and are easy to rinse out of the fabric and give reproducible "short" paste rheology (soft solid state). Flour paste is made in a similar way to starch paste; it's sometimes used to thicken aluminum and iron mordants. Starch paste created from rice flour have been used for several centuries in Japan and is still used today as a starch printing technique on fabrics.
The way this technique works is that you take the paste and put it on the fabric in which you don't want any dye to adhere to such as calico prints. If you want an indigo dyed shirt with white dots then you'll put that paste into small dots all over the fabric. When the fabric get submerged into the dye, the starch will prevent it from becoming blue. The end result is the starch will brush off after it dries, leaving white dots all over the fabric. Over time these dots will fade away whereas discharge printing (we'll talk about that later) will stay no matter how many times you wash/wear it. The only way to differentiate between starch and discharge printing is to look on the underside of the fabric, if you see the pattern leaked through then that's discharge printing but if you don't see it then it's starch printing.