Short answer: Fabric changes and makes delivered light uncertain. Visible glow through clothing does not establish wavelength-specific transmission or a treatment dose.
What controls
| Factor | Verify | Do not assume |
|---|---|---|
| Device | Exact manual, intended use, mode, output documentation, distance, eye guidance | That another panel's settings transfer |
| Fabric | Material, color, thickness, layers, moisture, coverage | That visible light equals a known dose |
| Outcome | Condition-specific evidence | That longer exposure compensates for clothing |
Do not calculate a medical dose from unattributed consumer specifications or increase time to compensate for unknown transmission.
Bottom line: Clothing makes delivery uncertain; follow the exact manual and condition-specific professional guidance.
Evidence and limits
Photobiomodulation evidence is condition-, device-, wavelength-, and dose-specific. Findings from a studied device or indication do not automatically transfer to a consumer LED panel.
Source: clinical photobiomodulation review.