2022.12.16
Especially FAQ #12 BG layer is created when saving PSD

If you save the PSD with the background color specified, the specified background color will be automatically created as a “BG layer”.
If you don’t want to create a BG layer, set the background color to “Transparent”.
See below for how to make the background color transparent.
Index
PC
Check “Transparent Background” from the “View” menu.
iPad
① From the command bar menu, tap “Background color”.
② Turn on “Make Transparent”.
iPhone
① Open the paint screen of the work you want to change, and tap “Background Color” from the command bar menu.
② Turn on “Make Transparent”.
Android
① Open the paint screen of the work you want to change, tap the “Edit menu” on the command bar,Tap “Canvas Settings”.
② The canvas setting window will be displayed. Tap the canvas background color.
③ Turn on “Clear”.
▼Related words
I want to delete the BG layer
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