As with any fast-growing technology that shifts paradigms, RFID has raised some new issues as more and more tagging is done at customer premises; especially in case of asset tracking, warehousing and retail applications. Due to large number and complexity on kind of assets to be tagged, it is becoming more and more critical to select and affix the RFID Tags in correct manner.
A lot of RFID projects fail due to improper tag selection and wrong tag application methods.
General Tag Selection and Placement Factor
In selecting an appropriate tag location, several factors should be considered in case of any kind of asset tagging.
Orientation
Most RFID tags read best when presented in a specific orientation relative to the reader antenna. A tag in the wrong orientation may experience radically reduced read range or may not read at all. Experiment to determine the best orientation for a specific tag/reader combination, and ensure the tag is applied in the proper orientation.
Proximity to Metal
Metal presents a particular challenge to RFID. Most RFID tags experience reduced performance when used near metal. A tag placed directly on a metal surface will likely not read at all.
Some RFID tags are specifically designed for use on or near metal. These tags typically have a special housing which provides a gap of controlled thickness between the tag antenna and the metal surface or have a built-in metal foil (so the tag brings its own metal to work anywhere). The tags are also tuned to optimize performance near metal.
Mount-on-Metal tags by design can only be read from the exposed portion of the tag, opposite the metal. It is almost impossible to read a Mount-on-Metal tag from the other side of the metal surface.
Some tags are optimized to work on metal only. It is important to ensure that for those tags, the base is in close contact with the metal surface. Any nonmetallic spacer placed between the tag and the surface may result in a reduction in performance.
Moisture
Although most tags are physically unaffected by water, the read range of some tags diminishes significantly in the presence of moisture. UHF read range is strongly reduced while the tag is wet. If it is suspected that a tag will be exposed to moisture, rain or snow, be sure to test the tag in the moist environment to ensure that it will perform as expected.
Mechanical Strength
Ensure maximum contact between the tag and the surface. This is especially important for adhesive fixation. Maximum contact will help to ensure that the tag remains in place when exposed to mechanical shock and vibration.
Obstructions
In general, RFID tags do not require line-of-sight to read in case of non-metallic and non-fluidic assets. Be sure however, to test tags in their final operating environment, to prevent any unforeseen interference from obstructions.
Fixation Methods
There are multiple tag fixing methods for different type of tags but the following two types of methods are most commonly used:
- Adhesive:Adhesive fixation may be one of the simplest methods to implement and typically results in the maximum possible read range for a specific tag. Regardless of the adhesive used, always ensure that the tag and surface are clean, dry and free of debris to ensure maximum bond strength. Although the bond may set quickly, total curing time may be different for different adhesives. Once applied, pressure and moderate heating can be used to create an even stronger bond. It is a good practice to give a curing time of at least 2 hours for any adhesive being used. When a stronger adhesive bond is required, or the application environment is harsh, a silicone sealant or acrylic adhesive tape may be used.
- Mechanical Fasteners / Riveting: have holes through which a screw or rivet can be used to secure the tag mechanically. This method is recommended for applications that involve a high risk of mechanical stress, aging or in which the temperature during fixation is too low to promote a strong bond using the adhesive method. Select a screw or rivet that is appropriate for the surface material to which the tag is being applied.
Selecting a Tag Based on Intended Use
The most important step when deploying RFID is to consider how you or your customer will use it. There are many applications for RFID, and each one has unique objectives and requirements.
Here are some of the most common:
- Device pairing & validation
- Enabling the customer to track the device
- Enabling the OEMto track the device either internally or for maintenance or life cycle management
- Tracking a device through a process, like sterilization
- Supply chain management
Focusing on end use and business processes will determine what performance attributes you need in the tag. For example, a device validation application will require a tag with security features to prevent counterfeiting. If you just need general asset tracking, then a longer read range will be required.
Once you’ve identified the business processes, there are a number of factors to consider when selecting a tag.
Material Compatibility
To achieve reliable performance, an RFID tag has to be compatible with the surface to which you mount it. This is because certain surface materials like metals interfere with RF waves.
For example, if you need to mount a tag on a metal surface, you’ll need a multi-surface or mount-on-metal tag. If you mount a tag designed for non-metal surfaces onto a metal surface, the tag won’t work at all.
It’s also worth considering how the materials surrounding the tag will affect readability. In spaces with high quantities of metal, metallic interference can reflect and alter radio waves. Moisture can also cause interference, as it absorbs RF waves.
Environmental Conditions
There are a number of environmental conditions that impact the choice of a tag. Adverse chemistry, rough handling, vibration, dust, weather, heat cycles and extreme temperatures are all conditions a tag might face when mounted to a device. For tracking assets in extreme environmental conditions, you’ll need a tag with enough durability to withstand the punishment without hurting performance.
Business Processes
Within a single application, a tag can be used multiple ways. The business process and the way people will use the tag will inform the tag you need.
For example, RFID tags for servicing applications will require different read ranges depending on how technicians use them. If they use them to identify devices sitting on their desk, you’ll only need a read range of 1 foot. But if the service technician needs to identify one unit in a room of 100 units, you’ll need a long range tag.
Geometry
Once you’ve designed your device, you’ll need to find a place to mount or embed the RFID tag. If you’re far along in the development cycle, there likely isn’t much flexibility to alter the product to accommodate the tag. So, you’ll have to select a tag with a geometry that fits the device.
This involves answering a few questions:
- Where are you going to mount the tag?
- What direction does it need to face?
- How will you mount it?
In situations with tight geometric constraints, working with a custom tag can provide a give and take that makes it easier to embed the tag in your device.
Tag Cost
The goal of deploying in RFID is to achieve a return on investment. RFID can provide that return either directly to the OEM or indirectly as a feature that makes products more attractive to customers. Often, that means trying to get the most functionality at the lowest price.
For product developers, tag selection is constrained by price, which must be low enough to still deliver a solid ROI. Because of this, projecting your potential costs and returns is an essential part of selecting a tag.
RFID provides two important benefits. First, it reduces the amount of labor in a process by automating the collection of data. How much labor time RFID saves is a major driver of the ROI for RFID. The other benefit of RFID is improving the accuracy and timeliness of data. No more data input errors and no waiting for someone to sit at a terminal and transcribe the data from a worksheet. Information is accurate and delivered in real time. Calculating the ROI of this benefit is a little more difficult, but there is no doubt about the value of highly accurate and timely information about your company’s products.
When to Use Custom Tags
Sometimes an off-the-shelf tag can’t meet the requirements of an application. Finding the right combination of materials, durability, geometry and read-range in a ‘off-the-shelf tag’ is a big ask. Fortunately, you can engineer your way out of this by developing a custom tag that has exactly the right combination of attributes for your application.
The path to developing a custom tag can be difficult. You will want to partner with a firm that has substantial RFID experience, and a track record of solving the types of problems you face. You will need a product development partner who can create custom designs at the lowest possible cost. Often, customers need the development process to go quickly, as well.
Some vendors with the right design skills and experience have very high volume thresholds, like one million units, before they engage in custom projects. Fortunately, there are vendors with low cost, speed and the right design skills out in the market.
If you’re using a custom tag for a product you’re developing, you’ll need to be able to work closely with the custom tag design. Because of this, many product developers partner with RFID providers in their time zone, speeding up the development process while making it more interactive.
Conclusion
Embedded RFID makes the tracking and management of OEM products much easier. But, to achieve the optimal result, product developers will need to integrate RFID tags in a way that optimizes the performance of the system.
Introduction to RFID Tags
As with any fast-growing, paradigm-shifting technology, RFID (Radio Frequency Identification) introduces new challenges—especially in high-volume applications like asset tracking, warehousing, and retail. With the wide variety of assets to be tagged, selecting and applying RFID tags correctly is critical. Many RFID projects fail due to inappropriate tag selection or poor application methods.
General Factors for RFID Tag Selection and Placement
When choosing the right RFID tag and where to place it, consider the following technical and environmental factors:
- Orientation
RFID tags work best when aligned correctly with the reader antenna. Improper orientation can dramatically reduce read range or even prevent the tag from being read. Always test tag-reader combinations for optimal positioning before deployment.
- Proximity to Metal
Metal interferes with RFID signals. Standard RFID tags placed directly on metal will often not work. Use mount-on-metal tags specifically designed for such environments. These tags have built-in spacing or shielding to enable functionality near metal surfaces.
Note: These tags can only be read from the side opposite the metal.
- Moisture
Moisture, especially water, affects RFID performance—particularly for UHF tags. Although most RFID tags are waterproof, their read range may be significantly reduced when wet. Always test tags in their actual operating environment.
- Mechanical Strength
Tags must adhere securely to surfaces. Especially when using adhesive methods, full contact is necessary to withstand shocks and vibrations. A weak bond can cause tag failure during operation.
- Obstructions
RFID doesn’t require line-of-sight—but dense materials like metal or liquid-filled containers can obstruct signals. Always test tags in the field to detect any interference or blind spots.
Common Tag Fixation Methods
- a) Adhesive
- Simple and commonly used
- Supports maximum read range
- Clean and dry the surface before application
- Allow 2+ hours curing time for most adhesives
- For harsh environments, use silicone sealants or acrylic adhesive tapes
- b) Mechanical Fasteners / Riveting
- Ideal for high-vibration or rugged environments
- Use screws or rivets through built-in holes
- Suitable when temperature or surface conditions prevent strong adhesive bonding
Selecting a Tag Based on Intended Use
The use case will guide which tag you should select. Ask: What do we need the tag to do?
Common Use Cases:
- Device pairing and validation
- OEM asset lifecycle tracking
- Customer-managed asset visibility
- Process control (e.g., sterilization tracking)
- Supply chain tracking
The tag’s attributes—range, durability, security—should match the goals of your business process.
Key Considerations in RFID Tag Selection
- Material Compatibility
The tag must match the surface it’s mounted on. For example:
- Mount-on-metal tags are necessary for metal surfaces.
- Using a tag on an incompatible material can result in complete tag failure.
Also consider the surrounding environment—metallic or moist environments can degrade signal strength and accuracy.
- Environmental Conditions
Tags should be durable enough for:
- Harsh weather
- Heat cycles or freezing temperatures
- Vibration, dust, chemicals, or UV exposure
Tag performance should be validated under expected real-world conditions.
- Business Process Fit
Different uses demand different read ranges:
- Close-range (e.g., technician scanning at a desk): ~1 foot
- Long-range (e.g., scanning many items in a room): 10+ feet
Tag performance should be tuned to fit the way people interact with the system.
- Geometry
Available space and tag orientation play a big role. Ask:
- Where can the tag go?
- What size/shape fits the device?
- What direction should the tag face?
Custom-shaped tags may be required for tight or constrained mounting locations.
- Cost and ROI
Tags range in price based on features, materials, and durability. When selecting a tag:
- Project ROI: What labor, time, or accuracy improvements will you gain?
- Consider long-term savings in data entry, reduced errors, and faster processes
Tag price should balance functionality and business value.
When to Use Custom Tags
Off-the-shelf tags may not always meet specialized requirements. Custom tags offer:
- Tailored geometry and performance
- Optimized materials for specific environments
- Integration into the device design
However, developing custom tags requires an experienced RFID partner—preferably one in your time zone for smoother collaboration and faster iterations.
Some vendors only support custom designs for high volumes (e.g., 1 million+ units), but there are others with lower minimums and faster turnaround.
Conclusion
Embedded RFID can transform asset management and device tracking. But success relies on choosing the right tag—and applying it correctly. By focusing on tag selection criteria such as material compatibility, environmental conditions, geometry, and end-use goals, you can design RFID deployments that are robust, accurate, and cost-effective.