how to resize items without raising and lowering them?

i used to be able to make items smaller or bigger but it’s been like a year and i’m still trying to find a way to make it work again. i’ve tried pressing just [ or ], i’ve tried pressing shift and the brackets, i’ve tried control and the brackets. i have cheats on so i tried turning them off and everything just makes the items raise and lower. i’m really at a loss and i’m not sure what else to do. any help would be greatly appreciated!