What Is Dryness Index?

Updated 2026-08-02 · Soft Care Guide Editorial Team · Reviewed by Editorial Team · Fact Checked

Direct Answer

The dryness index is a measure of how dry a diaper surface stays after absorption, combining rewet testing and surface moisture assessment.

Key Takeaways

  • The dryness index is a measure of how dry a diaper surface stays after absorption, combining rewet testing and surface moisture assessment.
  • How it works: Manufacturers assess dryness via rewet tests (liquid returning under pressure) and surface moisture sensors or sensory panels.
  • Premium diapers tout high dryness scores based on low rewet and dry topsheets
  • Myth: Dryness is just marketing. It is measurable via rewet and surface moisture testing

How Dryness Index Works

Manufacturers assess dryness via rewet tests (liquid returning under pressure) and surface moisture sensors or sensory panels. A high dryness index means the topsheet stays dry to the touch even after absorption and pressure. It is influenced by SAP retention, core design and topsheet material. Brands use it to compare products and support dry-skin claims.

Examples and Applications

  • Premium diapers tout high dryness scores based on low rewet and dry topsheets
  • Dryness testing combines instrumental rewet with sensory touch panels

Dryness Index vs. Related Terms

TermWhat it isKey difference
Rewet rateDryness IndexRewet is the objective measurement; dryness index is the composite product score

Limitations and Common Misconceptions

  • Myth: Dryness is just marketing. It is measurable via rewet and surface moisture testing
  • Myth: Dry topsheet means dry skin. It strongly correlates but real rash risk also involves fit and changing habits
How is dryness measured?

Via rewet tests and surface moisture assessment — liquid returning to the surface under pressure.

Why does dryness matter?

A dry surface keeps skin healthier and reduces rash risk.

References

  1. BASF - Superabsorbents (HySorb / SAVIVA), how SAP works — BASF (accessed 2026-08-02)
  2. Pampers Official - What's in a Pampers diaper (component materials) — 品牌官方 (accessed 2026-08-02)