With correctly scaled (icon for recipe and item is correctly scaled in inventory and crafting tab) icons, the alt view for entities is at the same time not correctly scaled.
For https://mods.factorio.com/mod/CapsuleAmmo it means the items introduced gets a 1x1 pixel sized icon in alt view on assemblers and in chests even though the code is correct and is using the proper bug workarounds with invisible first layer 69221.
[1.0] Alt view layered icon scaling issue
Re: [1.0] Alt view layered icon scaling issue
I'm gonna move this to modding help instead of won't fix, so it can be helpful to others.
In GUI, the icon is scaled so that first layer fills the slot.
In game, the icon is rendered with scale you defined it with.
So if you use 1x1px first layer placeholder and configure subsequent layers so that they operate within the 1x1px region, that's what you'll get in the alt-view, while GUI magnifies this to fill the slot.
Either use 32x32px base layer, or set scale 32 to your 1x1px base layer.
In GUI, the icon is scaled so that first layer fills the slot.
In game, the icon is rendered with scale you defined it with.
So if you use 1x1px first layer placeholder and configure subsequent layers so that they operate within the 1x1px region, that's what you'll get in the alt-view, while GUI magnifies this to fill the slot.
Either use 32x32px base layer, or set scale 32 to your 1x1px base layer.