"Duplicate" files on my USB stick

I transfer .OUT files from my PC, as generated by Lightburn, to my TopWisdom cutter via a UAB stick. Since the latest but one Lightburn version (I’m now on 1.3.01) when the cutter reads the USB drive I see the file I want to transfer plus another version of the file prefexed with a dot underscore, “._”

If I try to load this file it says it is a bad format. This is not a big road block in that as long as I select the correct file everything is fine but it is a bit of a pain when you have lots of files and are in a hurry.

These versions of the file are small - only 4K.

When you look at the contents of the USB stick on the computer, these “shadow” / “duplicate” files are not visible unless you show Hidden Files.

Any ideas?


Are these previously deleted files?

I’d be suspicious that the Mac isn’t doing this… Don’t know why it would prefix it such, most Unix based os’s will hide files that start with a ‘.’

One of the other Mac users or someone from the lightburn group would have a better idea of what’s happening… I can’t see much reason for lightburn to do this…


@jkwilborn is on the right track. These files are created by MacOS when using file tools and may be difficult to get around. You can use command line tools that don’t create those files. I imagine there may be a 3rd party file manager that might avoid this as well.

More information on StackExchange about this:
macos - Why are dot underscore ._ files created, and how can I avoid them? - Ask Different (stackexchange.com)

I can set my browser to show hidden files… I would think the Mac could do this also?


I believe you can configure Finder to show you the files but it will be difficult to avoid the creation of them using Finder. The OS uses these files to provide metadata that would otherwise be stored in HFS but can’t since the USB drive is likely in some FAT format.

Didn’t mean that it would prevent it, just allow you to delete it…

This type of thing, obfuscation of the file system, is one of my irritants…

I have a real hard time finding stuff on a windows machine…


Thanks for all these comments - I will look into the MAC side of things to see if there is anything changed here that is perhaps not clearing up stuff when files are written to the USB stick or something similar.


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