The reason T-shirt printers spray a pretreatment solution before printing on dark-colored T-shirts

Why do T-shirt printers spray a pre-treatment solution before printing on dark-colored T-shirts?

There are three main reasons:

1. White ink is composed of inorganic chemicals.

2. T-shirt fabric is cotton, which is organic.

3. The white ink used in standard digital direct-to-garment printers cannot directly adhere to cotton surfaces.

Below is a detailed explanation:

1. Before printing on dark T-shirts, white ink serves as the base layer. The primary component of white ink in T-shirt printers is inorganic chemical peptide white powder, while T-shirt fabric is organic cotton. These two components struggle to chemically bond and adhere firmly. Therefore, it is impossible for the white ink used in T-shirt printers to chemically react with the T-shirt fabric.

2. The white ink used in T-shirt printers lacks corrosive properties and physical adhesiveness. Consequently, direct adhesion of T-shirt printer white ink to the fabric with high colorfastness is unfeasible.

It seems like every approach hits a dead end. What can be done? The only solution is to employ auxiliary materials as a workaround. The components of the pretreatment solution are also inorganic chemicals, capable of reacting with the white ink used in T-shirt printers. Therefore, spraying a layer of pretreatment liquid before printing allows the white ink to chemically react with residues in the fabric, firmly adhering to the T-shirt surface and achieving color fastness. Consequently, applying pretreatment liquid is essential before printing on dark-colored T-shirts using a T-shirt printer.