Why can dye sublimation only be printed on polyester fabrics?

This is determined by its physical principles. Under high temperatures, only synthetic polymers like polyester have fibers that open up, allowing the vaporized dye molecules to enter. Natural fibers like cotton do not undergo this change under heat, so the dye cannot penetrate and lock into the fibers.

Can I do dye sublimation on black jerseys?

No, you cannot. Sublimation dyes are transparent and penetrate the fibers rather than covering them. Think of it like drawing with colored markers on different colored paper: on white paper, all colors are bright and visible; but on black paper, no colors will show. Therefore, dye sublimation must be performed on white or very light-colored fabrics to ensure accurate and vibrant colors.

What is the fundamental difference between dye sublimation and standard 'heat transfers'?

The biggest difference lies in the 'layers'. A heat transfer applies a layer of adhesive film with the design onto the fabric surface, which feels like an extra layer on top. In contrast, dye sublimation infuses the dye directly into the fabric fibers. The design and the fabric sit on the same plane, leaving absolutely no feel on the surface. This makes sublimation much more durable and breathable.

Can dye sublimation print metallic gold, silver, or neon colors?

No, it cannot. Dye sublimation uses CMYK four-color ink mixing to generate its color spectrum, which cannot produce special colors with metallic reflective or fluorescent effects. If your design requires these effects, you can consider combining dye sublimation with other processes such as 'foil stamping' or 'embroidery' to achieve them.