Discharge printing

Discharge printing is a process where printing of lighter colors is done onto fabrics having darker background. The dye in the garment is removed by replacing it with ink which leaves a soft texture on the fabric. Discharge printing works best on cotton fabrics because other fabrics are dyed in different processes and react less to discharge chemicals and therefore the dye does not break down.

Initially in discharge printing, the finished goods required steaming during the drying process which discouraged the practicing of this process. But the latest discharge ink systems react chemically and do not require steaming. These latest systems brought advancement and brought new openings in the area of screen printing.

Discharge printing produces vibrant, opaque colors on dark color fabrics. The depth, levelness and penetration can be controlled in discharged printing. Complex patterns and soft colors can be produced with immense clarity.

Discharge printing is best observed when the four color printing is done on black 100% cotton shirts. The print appears best only when it is exposed to the heat chamber.

The graphics are done with discharge printing to avoid the hindrance of the printed line when the dice is rolled. If at all the printing is done with plastisol it would change the speed of the rolling dice. The discharge print gives a smooth run for the rolling of the dice.

Discharge printing enables a clean and transparent print than the earlier discharge addictives which were used only for water base inks. Reduction is the keyword for discharge printing. The method of discharge printing changes from fabric to fabric, but the best fabric for this method is a pure cotton one.

Zinc-formaldehyde is used to remove the dye in the discharge process. Therefore, it is necessary to wash the t-shirts before you wear them. Zinc- formaldehyde free discharge is also available which does not need any washing before wearing it. This is proved to be a better process than the ordinary discharge printing process.

Use the right kind of fabric.

–      The fabric has to be 100 percent natural like cotton.

–      The dye on the fabric should be easily discharged. Cotton gives wonderful results in this process.

–      The fabric should be dyed right avoiding over dyeing. This generally happens when there is shortage of dye and therefore another color is dyed on top of this color. So when we try to discharge it, it results in the color which is below it.

It is important to check the fabric before starting the process. The fabric should be strong enough to carry the discharge process.

It is necessary to know the following points:

–      You should never overlap the colors if you want to print spots on the fabric.

–      Always go for transparent colors to show the dark background on the fabric. If you want to separate colors then go for primary colors as they produce good results.

–      Discharge printing is mainly economical for all-over prints because it is done by soft hands.

The discharge screen printing involves the following steps:

–      First the table is prepared by stretching the cloth and pinning it up on the table.

–      Now the paste is prepared to discharge the dye on the fabric. Remember to get your discharge paste ready a few hours before the process takes place.

–      Prepare the color discharge paste and apply on the fabric so that the dye becomes soluble and comes out before the fabric is ready for steaming.

–      Print the fabric and keep it for drying, steaming should be done within 24 hours to produce best results.

–      Once the steaming process is done, then wash the fabric thoroughly to get rid of the chemicals. Hang the fabric and allow it to breathe for about 30 minutes, this helps in developing color.

–      There you go!! The final wash is here. Wash the fabric in detergent to prevent loosing of any vat dye left on the fabric which helps in fixing the dye to the fiber. It is recommended to wash the fabric in slight lukewarm water.

Discharge screen printing is a long process and cannot be carried at home as there are chemicals used in this process. They have to be handled carefully by trained staff with perfection and patience.