If you’ve got tattoos and are interested in trying out wearable tech, there are a few things to consider before reaching for your wallet.

The bad news is that tattoos and wearables aren’t always compatible. It’s a known issue among wearable makers but isn’t apparent to many consumers. You can still occasionally stumble upon social media posts where tattooed folks strap on a new smartwatch only to find that the device doesn’t work well — if it works at all. In the case of the Apple Watch, for example, tattoos can interfere with wrist detection, making the device unable to recognize that you’re actually wearing it.

This is because the majority of wrist-based wearables rely on photoplethysmography (PPG) sensors. These optical sensors work by shining light into your skin and determining various biometric data based on how much light is reflected back. It’s a neat, noninvasive way to keep track of your health metrics, but it’s inherently flawed. If you think back to elementary school science class, lighter colors reflect more light, while darker colors are better at absorbing it. This is why these PPG sensors can be confused by people with darker skin tones or lots of tattoo ink.

It’s not a fun answer, but currently, the only way to guarantee that a wrist-based wearable will work as intended is to avoid getting the top of at least one wrist tattooed. (Or, at least, take note of where the sensor array will sit on your skin and work with your tattoo artist to design around it.) But what if you already have tattoos covering every inch of both wrists?

Epoxy stickers

A popular Reddit hack for getting smartwatches to work with tattoos is epoxy bottlecap stickers. These stickers are inexpensive — often under $10 on Amazon for 50–100 stickers — and you can stick them on the sensor array. Anecdotally, many users have found this tends to fix issues with wrist detection and, in some cases, may even solve issues with heart rate monitoring and workout tracking. That said, your mileage may vary. On the Samsung Galaxy Watch 4 and 5, for example, using the sticker may prevent body composition analysis.

Still, this is a cheap enough workaround that, if you have access to a friend’s smartwatch, can be easily tested before you actually buy the device.

Chest straps are your friend

If your primary focus is heart rate data during exercise, that’s an easy fix. Chest straps, like the Polar H10 or Garmin HRM-Dual, are a great and affordable alternative.

Unlike smartwatches and fitness trackers, chest straps don’t use optical sensors. Instead, they use electrocardiography. These straps have electrodes to read your heart’s electrical activity to determine your heart rate. All you have to do is moisten the electrode beforehand so it can conduct electricity and make sure the chest strap, which is usually an adjustable elastic band, is secure. That’s it. No fancy LEDs involved.

Technically, chest straps are also more accurate than their smartwatch counterparts. That’s because electrocardiography measures your actual heartbeat, while PPG sensors measure your pulse as a proxy for your heartbeat. It’s why chest straps were considered the gold standard in the early days of wearable technology. Nowadays, companies have dramatically improved PPG sensors and heart rate algorithms on smartwatches and fitness trackers, but chest straps are still less prone to error.

Many chest straps also include Bluetooth and ANT Plus connectivity, so they can easily communicate with gym equipment and smartphone fitness apps. You can even pair them to smartwatches for heart rate data. This might be a feasible workaround for some, but unfortunately, tattoo ink can also prevent your smartwatch from recognizing that you’re actually wearing it. There’s no real way to tell what types of tattoos confuse smartwatches the most, though it tends to be those with dense designs and darker ink.

The problem with chest straps is they’re never going to win the comfort award. If the elastic wears down or if you don’t secure the band, it can fall down your waist mid-workout. If you wear sports bras, your chest area might feel extra tight. Chafing is also a concern, depending on how the chest strap is worn. They’re also not suited to 24/7 heart rate monitoring. If that’s your ultimate goal, you might find it more convenient to opt for a different wearable form factor.

Smart rings

If you haven’t tattooed the underside of all 10 fingers, smart rings might be a good option for all-day fitness tracking. They’re not as popular as smartwatches, but they have a few advantages. They’re more discreet and more comfortable to wear, and their PPG sensors shine light into the bottom side of your finger. The finger is actually preferable to the wrist for heart rate monitoring as there’s less noisy data to filter out. Plus, the skin on the underside of the finger has less melanin (and probably ink) to confuse PPG sensors.

The Oura Ring is the most successful and widely known smart ring. Although it’s primarily a sleep and recovery tracker, it has since added workout heart rate, blood oxygen monitoring, and period tracking. You also get the basics like step tracking, resting heart rate, and reminders to move every hour. In addition, it includes some metrics that smartwatches and fitness trackers have only recently started adding, like sleeping body temperature, respiratory rate, and heart rate variability. The downside is the ring is pricey at $300 with a $6 monthly subscription, and you miss out on some proactive health features that are on advanced smartwatches (such as abnormal heart rate alerts and atrial fibrillation detection), as well as push notifications, timers, alarms, and emergency calling.

This is an area to keep an eye on, as it’s still a nascent wearable form factor. For example, Movano Health is working on Evie, a smart ring that’s currently pending FDA clearance. If successful, the Evie ring would be a medical-grade device with a lot of clinical testing that tracks a ton of heart rate metrics and blood oxygen. It’s not a solution for right now, but it’s a sign that smart rings hold promise as an alternative for people with sleeves or wrist tattoos.

Wearables you wear elsewhere

If you’re not keen on a chest strap and you happen to have a free patch of skin on your arm or forearm, there are arm-band heart rate monitors like the Polar OH1 or the Peloton Arm Band. These use optical sensors, but they’re more comfortable and conveniently located than chest straps. Unlike chest straps, you can also more easily view feedback on your heart rate zones.

Or if you listen to music or podcasts while working out, there are earbuds out there with heart rate monitoring capabilities like the Amazfit Powerbuds Pro and the Anker Soundcore Liberty 4. Technically, the ear is also better than the wrist in terms of accuracy — provided you get the proper fit. This can be challenging as it’s notoriously hard to get a good fit with normal earbuds, but it is an option.

Alternatively, you could invest in a niche wearable like the Whoop 4.0. It’s expensive due to the $30 monthly fee, but the benefit is that it supports 24/7 health tracking. It’s similar to the Oura Ring. You won’t get notifications or proactive health alerts, but you will get in-depth recovery metrics, heart rate data, and sleep tracking.

Another benefit is that Whoop has launched its own clothing line as well, so you can slot the tracking device into specially-made bras, boxers, leggings, compression shorts, shirts, and arm sleeves. For example, Whoop’s sports bra has a special pocket on the side near your ribs. You slot the tracker in there, and it’ll take heart rate readings from that part of your skin. As for accuracy, the company claims that its tracker has been validated for use on the arm, wrist, torso, leg, and waist. It’s admittedly a pricey alternative, but one of the few that truly lets you wear a tracker on any part of your body.

None of these solutions are 100 percent perfect, but as mentioned, the PPG sensors favored by smartwatches and fitness trackers are inherently flawed. No matter how much a company refines its algorithm, it can’t change the fact that darker colors don’t reflect light well.

Tattoos are a form of artistic expression and often hold emotional value — you shouldn’t have to alter or remove any to use wearable tech. But until companies get more creative and find an alternative to wrist-based PPG sensors, these are some of the best available alternatives.