I attempted to make a pvp texture pack, and I started to work on the inventory. Tell me if you like it so far, and what I can improve!
I made this in paint.net first of all, which is free and easy to use. Second, I opened another window and pasted a picture of a galaxy that I had. I resized that picture to very small, allowing me to resize it to the point I wanted later. After I finished editing the inventory pixel by pixel, I made a new layer and pasted the picture into that layer. Then I edited the opacity and made it transparent enough where you could see the inventory, but have that background effect. I am not the best texture pack maker, but if you want to know more, you can PM me or use google/Youtube