Huh. I tried it last night with these two glasses (so product itself is actually trans) to compare and the trans design gave me a trans png, the one with a black background gave me a black png.
I just tried it with this t-shirt, which has a trans design so the background color is determined by the product color, and the png downloaded does indeed have a purple background.
[About My Dog] Show Dog Brag T-Shirt
It seems like if you’ve left the background transparent, the artwork downloaded reflects the product background color (as evidenced by the clear shot glass and purple shirt). Which would be why putting her design on a transparent wall decal works. But if you’ve set a background color (as she said she did), you get that color on the download.
This was in the same product category and I had made the background on all of them white. About 80 percent just showed the design on a transparent background. The rest showed the white background and it looked like the product.
I wonder if this has anything to do with the option to set white as transparent in the design tool. And/Or perhaps because with the new Instant Downloads, those in-situs are using white to represent trans areas. Maybe when the system produces the artwork to download, it’s just getting confused on white vs trans now.
I have a couple of products (pillows, disposable cups) where I set the background as solid white even though my design over it was trans and those downloaded correctly with a solid white background. However, I just tried it with a paper product,
and in this case, the white version, where I do have white set as a solid background color, the png downloads as transparent. (The black version downloads with black background.)
I don’t have the right kind of products & designs in my store to test more but so far it seem like the issue is only with white vs transparent, and only on paper products. (I’m kind of assuming most of the products you were working on yesterday were paper products.)