About half of our micro shipments are user programmable. Unfortunately, our different technology means that for the most part, we are not supported by commercial programmers. And so if the customer is not using something like ISP (In System Programming), then we have to program and label the parts for them.
We can easily program the parts on our automated testers. Indeed, for larger customers, we include the programming as part of the final test.
The difficult part is in the labels. We have to have a label and ink that will survive the RoHS surface mount temperature profile of about 250C and the subsequent board cleanings. And the inexpensive Avery labels won't stand up in that environment.
It turns out that you can buy Kevlar labels that will stand up, and this is what we use. We also use our barcode printer with the plastic film ink. The only problem with this is that when we load the labels into the printer, it will waste about two feet of them as it goes through the alignment cycle. Since that is about $10 worth of labels, this causes me pain, especially since I have to change the labels out when we are done to switch back to regular bar codes.
Eventually, we will replace this with a laser writer. We have one that we bought at auction, but it is in storage now since we are very short on floor space in our manufacturing area.