Earlier this week we reported on a potential problem with the Apple Watch sensors not being able to read through tattoo ink. Some people who have artwork etched into the skin on their arms are having some troubles with the newest Apple device and some of its features. Apple has now confirmed that issue with some added information into their support page for the Heart Rate sensor on the Apple Watch.

Permanent or temporary changes to your skin, such as some tattoos, can also impact heart rate sensor performance. The ink, pattern, and saturation of some tattoos can block light from the sensor, making it difficult to get reliable readings.

The Heart Rate Sensor on the Apple Watch detects your heart rate through photoplethysmography, a technology that senses your heart rate through light. Tattoo ink can block that light. Hence, how some people with arm art might have some troubles with this feature.

For more information on the Heart Rate Sensor, visit https://support.apple.com/en-us/HT204666.