* Removes sizing, finishes, and oils: Fabrics often have sizing agents (like starch) or finishes applied during manufacturing. These substances can prevent the dye from properly penetrating the fabric, resulting in uneven or less vibrant colors. Natural oils from handling the fabric can also interfere with dye absorption.
* Removes dirt and residues: Even if the fabric looks clean, it may contain dirt, dust, or other residues that can hinder the dyeing process.
* Ensures even dye absorption: A clean fabric will absorb the dye more evenly, leading to a more uniform and professional-looking result. If there are impurities on the fabric, the dye might adhere better to some areas than others.
* Prevents unexpected color changes: Some residues on the fabric might react with the dye, potentially altering the final color in unpredictable ways.
In short, pre-washing ensures that the dye can interact directly with the fibers of the fabric, resulting in a more successful and predictable dyeing process.