At Moody V, there's a pretty dope variety of sizes, absorbencies, and functions of pads. There are liners, thong liners, regular absorbency pads, heavy absorbency pads, and overnight pads. Anyone could use each of these pads, and use them in different ways! If you wanna read testimonials or reviews about how people use their Moody V cloth pads, check out the review section on Etsy, here!
The best cloth menstrual pads for a heavy flow would be either Moody V's heavy absorbency, or the overnight pads. These pads are made with cotton flannel, cotton terry cloth (towel material) inside for absorbency, and a layer of polyurethane laminate underneath the terry cloth (the same material that's in cloth diapers!)
Moody V overnight pads differ from the heavy absorbency pads in that they are longer, flare at the back, and it's waterproof lining is actually in the base of the pad as opposed to in the pad core alone. So, that means that if the pad is fully soaked, even the wings function as a protective barrier! Yas, queen!
The overnight cloth pads are made with cotton flannel, terry cloth, and a waterproof laminated fabric lining! The water proof lining is called polyurethane laminate, aka PUL.
Someone with a heavier flow who likes to use a menstrual cup or tampon at any point in their period might like to check out Moody V's cloth liners as a lil backup protection, ensuring that any leakage ends up on a cloth pad instead of your undies.