I use an old Britta filter with some cheese cloth to filter my old IPA. Pour in the old nasty stuff, let it sit for a day, pretty clean reusable IPA comes out the other end.

Open a new blender project. From the drop down menus along the top, Select open, import, import STL, then find your first stl in the file explorer. Repeat this to import the second stl. Drag and rotate both objects until they’re lined up how you want them. Select both stls at the same time. Right click and select “merge”. Then in the drop down menus, find export, export as STL. Save it as your new STL. Open this new stl in your preferred slicer program, and you’re good to go!

Use blender, it’s free and can easily merge stls.

Does it matter? Have you tried running it with the mandarin characters? Is something not working?

Posting a screenshot of your settings may help to see what is going on. And pics of some calibration prints.

Have you looked up settings for this new resin? Or run calibration test prints with it? If you’re using the settings for the old resin with a different kind of resin it won’t be right. It looks like your exposure time is too low, the resin isn’t being cured enough at each layer so it’s not adhering. Bump up the exposure time a lot and see if anything comes out. Also bump support thickness and connection thickness up. You can see the supports not even making full connection with that spear in the photo.

I use blender for editing STLs. Import your files, overlay them where you want them, select both objects, apply the boolean to subtract differences. This should cut the images out of the disc as a negative. Export as STL.

If I was browsing through furniture on Etsy and the first image was that imprecise looking bezel I would close your shop and keep looking. It just looks like sloppy cutting rather than the hand of the artist. I would find other ways to show the artist’s hand, maybe a hand-carved element or something. Especially for this style of piece which is emphasizing clean lines, having a wavy line looks sloppy not intentional.

Nice