Where to Place an RFID Inlay

Printing and encoding RFID “smart labels” with an RFID-enabled printer has traditionally been difficult; a classic case of “the Devil is in the details.”  One difficulty users have wrestled with has been “inlay placement.”  Inlay placement refers to the location of the RFID inlay under the label’s face stock.  Although inlays are generally oriented horizontally under the face stock, the inlays can be located towards the bottom of the label, towards the top, or anywhere in between.  In the picture to the right, for example, the inlay is relatively close to the bottom of the label, the “leading edge” as it is often called, because this edge comes out of the printer first. 

Almost every printer brand – and even model – has traditionally had detailed, complex specifications regarding inlay placement, with different specifications for each and every inlay on the market.  The location of the inlay has to be a particular distance from the leading edge of the label in order to maximize the printer’s throughput (speed).  Just a millimeter or two either way, and the performance of the printer can suffer dramatically.  What a mess.  Given that printing and encoding RFID labels is already slower than printing traditional barcode labels, any further loss in performance has often been catastrophic for the end-user.  Waiting for your RFID labels to print and encode can hold up an entire production line.  This all meant that for your printer brand and model, you needed to make sure to order labels with an optimal inlay placement. 

Precise inlay placement also causes some additional problems: 

• It makes selecting labels more difficult. Users need to order their labels very carefully to ensure correct inlay placement.  Does your purchasing department understand inlay placement?  
• It can cause delays in sourcing labels.  Often, a convertor (label manufacturer) will have exactly the label size you need – but with incorrect inlay placement for your printer.  To get labels with optimal inlay placement, the convertor needs to configure their entire production line and run a new batch of labels for you.  This can take several days to several weeks. 
• Finally, requiring a specific inlay placement can mean that users may pay more for their labels.  A quick Google search of classic paper thermal transfer 4×6 RFID shipping labels will show some surprising results.  The very same labels from the very same vendor can have dramatically different prices depending solely on inlay placement.  It all boils down to supply and demand, but if you are on the wrong side of the equation, you may have to pay significantly more for your labels. 

With Printronix Auto ID’s current line-up of RFID printers, these headaches associated with inlay placement are now a thing of the past.  Printronix RFID printers have a unique firmware (the software brains in the printer), which does what they call “Encode During Print.”  In clearer language, this means that the printer will first print some of the label, then switch over to encoding, then switch back to printing and finish up the label.  The printer will automatically either print or encode at any given moment depending on where the label is relative to the printer’s printhead and RFID encoder.  The traditional approaches for RFID printers were to either first print the entire label, then encode the RFID portion (“Print then Encode”) – or to first encode the RFID, then print the label (“Encode then Print”).  But with these traditional approaches, if the inlay is not optimally placed, then the printer needs to back- or forward-feed the label to align it for an operation (printing or encoding) at any given moment.  With Printronix’s Encode During Print functionality, back- and forward-feed are eliminated (other than to overstrike bad labels, which is another blog topic for another day), regardless of inlay placement. 

So far, we have been talking about labels like 4×6 shipping labels that allow different inlay placements.  But what about all of the RFID labels, “tags,” on the market that have predetermined inlay placement?  For example, on-metal tags, plant stakes, small pharmaceutical labels for cold-chain applications, “RTI” tags (Returnable Transport Items), etc., etc.  There are many such tags on the market, and more are being developed and released all the time.  These tags generally have a fixed inlay placement based on their physical design and on simple commercial considerations – they are meant to be “Off-the-Shelf” (OTS) products.  This is another area Printronix’s Encode During Print functionality shines even more.  Because the Printronix printers do not care where the inlay is located, you can use any of these tags and still achieve maximum throughput. 

And these unusual tags often pose physical feed challenges for RFID printers.  For example, on-metal and RTI tags are often thicker than normal smart labels, and they can have abrupt edges between labels, large gaps, etc.  Both Printronix’s T6000e and T4000 series printers were designed from the ground up to work with these more difficult constructions.  The printers are spec’ed for labels up to 1.2mm thick and are available in 4” and 6” print-widths, allowing you to print and encode a wide variety of tags from a single printer – all without sacrificing performance.  

Finding the right RFID solution is always a challenge and having the right resources and help are critical. If RFID sounds like a suitable solution for your business or you have additional questions, feel free to contact us at Barcodes, Inc. We’re always happy to help you find the right solution for your needs.