For FDM 3D printing, PLA is a durable and reasonably priced workhorse filament. However, other material developers assert that adding chemicals to PLA filament improved it, resulting in PLA+, an improved form of the substance.
The PLA + doesn't have a single formula. Manufacturers can source formulas and combinations or create their own. Most of the time, manufacturers are secretive about their formulae. But if you look hard enough, you can find a few things.
Because PLA plus should be less brittle and absorb less moisture than regular PLA, it may contain a trace of TPU.
PLA+ filament is marketed by material developers as a high-quality version of PLA that has some advantages over the standard version of the filament. As we've seen, PLA+ usually lives up to its promises, providing superior toughness and layer adhesion, among other advantages. Thousands of 3D printer users have reported positive results when using popular PLA+ filament brands such as eSun and Overture, demonstrating that these materials can perform well under the right printing conditions.
However, keep in mind that the term "PLA+" is not a guarantee of quality, and a standard PLA from a reputable filament manufacturer may outperform a PLA+ from an unknown seller.