Standard highlighters are generally safe to use on most types of paper, but there are exceptions. Highlighters contain fluorescent ink that is designed to be translucent, allowing the underlying text to remain visible. However, the ink can bleed through or cause feathering on certain paper types, particularly those that are thin or have a low-quality finish.
1. **Thin Paper**: Highlighters can bleed through thin paper, such as that found in some notebooks, Bibles, or newspapers. This can make the text on the reverse side difficult to read.
2. **Glossy Paper**: On glossy paper, such as that used in magazines or brochures, highlighter ink may not adhere well, leading to smudging or uneven application.
3. **Recycled Paper**: Recycled paper can vary in quality. Some recycled papers may absorb highlighter ink more readily, causing feathering or spreading of the ink beyond the intended area.
4. **Coated Paper**: Papers with a coated finish, like those used for photographs or high-quality prints, may resist highlighter ink, leading to smudging or a lack of vibrancy.
5. **Specialty Papers**: Papers with unique textures or treatments, such as vellum or parchment, may react unpredictably with highlighter ink, potentially causing smudging or uneven highlighting.
To minimize issues, test the highlighter on a small, inconspicuous area of the paper first. Additionally, using highlighters specifically designed for delicate or thin paper can help reduce the risk of bleed-through and feathering.