Most people call it a bath mat. You’ll also see terms like bath floor towel or hotel bath mat—these are towel-like, reversible cotton mats made to soak up water right outside the tub or shower. A bath rug is typically plusher and more decorative, and often includes a backing. Some cotton floor towels are specifically labeled “not a bathroom rug” to highlight that they’re flat, towel-constructed pieces without a thick backing. The best choice depends on whether you want quick absorbency (floor towel/bath mat) or a softer, decor-forward feel (bath rug).

It depends on what you value most. Consider these options:

• High absorbency: Cotton terry or chenille microfiber can soak up splashes after a shower.
• Quick dry: Waffle-weave or low‑pile microfiber tends to dry faster between uses.
• Non-slip support: Look for rubber/TPR backing to help reduce shifting on smooth floors.
• Low profile: Thin mats fit under swinging doors and dry quickly.
• Easy care: Many are machine washable; always follow the care label.

Rotating between two mats can help keep one drying while the other’s in use, which may improve freshness in busy bathrooms.

You’re likely thinking of a diatomite (diatomaceous earth) bath mat. It’s a thin, hard surface that absorbs water quickly and then releases it as it evaporates, so it can feel dry again sooner than fabric mats. Helpful tips:

• Care: Wipe after use and let it air out; some can be lightly sanded to refresh the surface—check the label.
• Placement: Use on a flat, dry floor so it sits level. If additional grip is needed, a suitable underlay may help.
• Cleaning: These aren’t machine washable; follow the manufacturer’s instructions.

If you prefer a softer feel underfoot, consider:

• Smooth cotton terry: Combed or looped cotton mats offer a familiar, towel-like softness.
• Low‑pile microfiber: Soft, velvety tops can feel gentle and reduce friction.
• Bound edges: Finished edges can help minimize rubbing around the perimeter.

Washing before first use with a mild, fragrance‑free detergent and thoroughly rinsing can help remove residual lint or finishing agents. Everyone’s skin is different, so if you have specific skin concerns, it may be best to consult a healthcare professional for personalized guidance.

Measure your space first, then match to common sizes:

• Small spaces: 16"x24" or 17"x24" works well at a shower door or pedestal sink.
• Standard tub: 20"x32" offers fuller coverage along a tub or vanity.
• Larger footprint: 18"x30", 22"x34", or 24"x36" can span wider vanities or double-sink areas.
• Toilet contour: U‑shaped mats (around 20"x24") are designed to sit at the base.

Leave a small border (about 2–4 inches) around the mat and check door clearance if your bathroom door swings over the floor. Choosing a low‑profile option can help where space is tight.