Cat & Jack
A mass-market value brand, not a plastic-free one. Cat & Jack's cotton briefs are cotton-bodied but described as "cotton with a touch of stretch," meaning elastane is blended into the fabric and the band rather than a pure-cotton knit. Several adjacent lines are more synthetic still - seamless hipsters run nylon/elastane and athletic/boxer-brief styles run polyester/elastane - and licensed character prints add plastisol-type graphics on top. Affordable and easy to buy, but synthetic content sits against some of the most sensitive skin.
How clear are their specs?
Target listings give a headline fiber content but often summarize it as "cotton with stretch" without always breaking out the exact elastane percentage or the band composition; content varies significantly across the underwear lines (cotton, nylon-seamless, polyester-athletic).
Products to avoid
Documented so you know what to skip — each still has a full breakdown and sources.