Is Zinsser primer better than Sherwin Williams?

Is Zinsser primer better than Sherwin Williams? Whether Zinsser primer is better than Sherwin-Williams primer depends on specific product and job. Zinsser is specialty primer brand owned by Rust-Oleum, known for stain-blocking and adhesion products like Bulls Eye 1-2-3, Cover Stain, and B-I-N shellac, which are widely considered top-tier for blocking severe stains and odors and sticking to difficult surfaces. Sherwin-Williams makes excellent paints and primers like Extreme Bond, Multi-Purpose, and Drywall Primer, which are high quality and favored by professionals for compatibility with Sherwin-Williams topcoats, good coverage, and durability. For heavy-duty stain and odor blocking, many professionals rate Zinsser B-I-N shellac better than most Sherwin-Williams primers. For general drywall and wood priming under Sherwin-Williams paint, Sherwin-Williams primers may be better matched for system performance and warranty. So Zinsser often wins for specialty stain-blocking and adhesion on glossy or problematic surfaces, while Sherwin-Williams primers are excellent for standard priming and integration with their premium paints. Choice depends on problem, for severe smoke or pet odor, Zinsser B-I-N is usually considered better, for new drywall under Emerald paint, Sherwin-Williams primer may be preferred.