So, as I said, I will show you how to make an inventory with a picture, let’s go.
First you need to take an inventory picture from some resource. ResourcePack/Assets/Minecraft/Textures/Gui/Container/Inventory.PNG
Next, we open the picture in any photo editor, but I will use Photoshop CS6.
Now we apply some picture or text and make it transparency at your discretion, but I made a Lemon test with an opacity of 80%.
Then we save and place it there from where and took this file. ResourcePack/Assets/Minecraft/Textures/Gui/Container/Inventory.PNG
And now in the game we choose this resourcepack and enjoy the result.
If you want to make the same inventory in creative, then you need to take the Tab_inventory file.png and do the same fraud with him. ResourcePack/Assets/Minecraft/Textures/Gui/Container/Creative_inventory/Tab_inventory.PNG
Well, on this I say goodbye, there was just_lemon with you, so far.