Man i pose all the time. How about alot of pasta i think that would make me thick possibly stronger but i really wanna harden up. Should i just try low reps for a few weeks?
Density is muscle fibers thickened over time, it is the contractile aspect thickening that gives the muscle a hard granite look, not the packing of glycogen and water into the muscle. You will see denser muscles on bodybuilders or athletes that have trained with a powerlifter base at some point (examples Yates, Coleman, Johnnie Jackson), drugs of course increase density but this can be done by training hard and heavy over time. Density takes time to achieve, most beginners and intermediate trainees do n ot have dense looking muscles, it takes time. If you want to see dense looking muscles look at trainees who have been working out for close to a decade or more. Genetics of course play a role, but you have what you have, unless you have access to gene therapy.
Get significantly stronger on your major movements for sets of 4-8 reps, round the routine out with higher rep training if you want to. Stick with it until you are satisfied with your density. Give it time to work.
Posing will not increase density, it will give you better muscle control though.
There is nothing magical about pasta that bread, potatoes, oats, or any other complex carb can do.