A method for determining a Plug Normal Stress Difference (ΔN1(P)) may include providing a test base drilling fluid that is characterized by N1(TB); adding a first concentration of a test particulate to the test base drilling fluid; adjusting the concentration of the test particulate in the test base drilling fluid to achieve a minimum concentration of the test particulate in the test base drilling fluid that will substantially plug a tapered slot, wherein the test base drilling fluid with the minimum concentration of the test particulate is characterized by N1(TA); and calculating ΔN1(P)=|N1(TA)|−|N1(TB)| wherein each First Normal Stress Difference is measured by the same procedure.