In general, dyeing synthetic fiber curly closure and bundles is not recommended—and in most cases, it will not yield the desired results, and may even damage the hair. The reasons and specific scenarios are detailed below:
1. Why Synthetic Hair Is Hard to Dye Successfully
Synthetic hair is made of man-made fibers (e.g., polyester, kanekalon, or modacrylic), which have a completely different structure from human hair. Human hair contains keratin (a protein that absorbs dye molecules), but synthetic fibers are non-porous and lack this protein-based structure. This means:
- Regular hair dyes (permanent, semi-permanent, or demi-permanent) designed for human hair cannot penetrate synthetic fibers. The dye will either sit on the surface and wash off immediately, or create patchy, uneven color.
- Even if some color adheres temporarily, it will fade drastically after the first wash, or rub off on clothing/pillows.
2. Risks of Attempting to Dye Synthetic Hair
Trying to dye synthetic bundles can cause irreversible damage, ruining the hair’s texture and appearance:
- Fiber damage: Harsh chemicals in hair dye (e.g., ammonia, peroxide) can break down the synthetic fibers, making the hair frizzy, brittle, or prone to shedding.
- Melting risk: If you use heat to "set" the dye (a common step for human hair), synthetic hair may melt or warp—most synthetic fibers can only withstand low temperatures (120–180°C/248–356°F for heat-resistant types), and dyeing often requires extra heat that exceeds this limit.
- Unpredictable results: The final color may be dull, streaky, or completely different from what you intended (e.g., a blue dye might turn the hair gray or green on light-colored synthetic bundles).
3. Exceptions: When Dyeing Might Work (With Limitations)
There are very few narrow scenarios where you can alter the color of synthetic hair, but these are not true "dyeing" and have strict constraints:
- Using fabric dye for darkening: Some people use fabric dyes (e.g., Rit Dye) to darken light-colored synthetic hair (e.g., from blonde to brown or black). However, this only works if you are darkening the hair (lightening is impossible, as fabric dye cannot remove color). The process also requires careful control of time, temperature, and dye concentration—even then, the color may look flat or unnatural.
- Temporary color products: For short-term color changes (e.g., a one-time event), you can use temporary options like:
- Colored hair chalks
- Temporary hair sprays (formulated for synthetic hair, if available)
- Colored mousses or gels
These products sit on the surface and can be washed out easily, with minimal risk of damaging the synthetic fibers.
Final Recommendation
If you want colored curly closure and bundles, it is far better to buy pre-colored synthetic bundles (many brands offer a wide range of shades, from natural tones to bold colors) than to attempt dyeing them yourself. Pre-colored synthetic hair is manufactured with color infused into the fibers, ensuring long-lasting, even color without damage.
If you already have uncolored synthetic bundles and want a temporary change, stick to temporary color products—avoid permanent or semi-permanent hair dyes entirely.