which NFC forum defined tags are you using?
We were using previously NFC forum Tag 1 tags, which was was provided to us by Innovision company and were known under its sales name Topaz. Since the Innovision was bought by Broadcom the product disappear from the market. Are there any other NFC forum Tag 1 providers? So far we are going with NFC forum Tag 2 NXP Mifare UltraLight C, but they have half a capacity as Topaz had...
Which software and contactless readers are you using to write the data to the NFC tags?
BR STeN
Most of the tags I am using are mifare classic with 1k memory. I got them from smartcardfocus.com.