Dyes are typically defined and categorized based on their ability to ionize, meaning their ability to interact with compounds of the opposite charge. Specifically, basic dyes are positively charged, cationic colorants. At the molecular level, basic dyes have amino groups, which are responsible for the molecule’s positive charge. Because of their positive charge, basic dyes react with negatively charged compounds. Therefore, the primary way in which the coloration process is achieved with basic dyes is by ionic bonding. In short, the positively charged molecules of basic dyes bond to the negatively charged compounds in the materials with which these dyes are used.
Because of their cationic or positively charged properties, basic dyes are used in a variety of applications for products with anionic (negatively charged) properties. For this reason, basic dyes can be problematic for recreational coloring or for use in the home environment. If not used with safety and caution, basic dyes can stain unintended materials, like the glass and plastic of containers, the porcelain and sealant of sinks, and the molecules of your skin and body (due to the negatively charged nucleic acids of your cells). So the chemical properties of basic dyes make them ideal for dyeing plastics like acrylic, dyeing paints, coatings, & stains, dyeing paper products, dyeing hair, and dyeing industrial products.
Basic dyes are known for their wide range of shades, their brightness and vibrancy, and their compatibility with synthetic, anionic materials. Basic dyes are highly preferred when coloring synthetic, cationic materials, such as acrylics, for example. Since other types of dyes such as disperse dyes typically yield pale colors when used with these types of synthetic materials, this is when basic dyes perform the best. When used with materials that are chemically compatible, basic dyes yield vibrant, bright, and lasting colors that other types of dyes are not able to achieve.