Mine isn’t marked, either, but I’m wrapping it in plastic to ensure I don’t electrocute myself or my seedlings!
I’ve got two different brands and they both feel the same on either side and neither one say this side up so I’m going with printed side down. I don’t think it really matters.
Got my racks set up with the mats and lights. Then I realized I haven’t put any thought into what I’m growing. Too much of a variety of seeds to grow some of everything and I don’t know everything I have off the top of my head so I get to go through seed packets now and make the torturous decision on what not to grow.
Quickly pulled cool weather stuff out and there’s 17 different things. Why do I have 6 types of bok choy?
I get to use my new automation controller to run the lights. Just need to snag a relay from work. The typical cheap plug in light/lamp timer I used last year had a couple of weird spots where it would turn off for about 5 minutes when it was supposed to be on. Drove me crazy seeing them turn off out of the corner of my eye every night.