Not all toilet paper dissolves at the same speed. If you are shopping for the "best" paper for your plumbing, look at these factors:
You can see for yourself how well your brand dissolves:
Most standard toilet paper is designed to dissolve in water, which is critical for avoiding clogs in plumbing and septic systems. Frank's Mr. Plumber
While toilet paper does not completely dissolve, it is generally considered to be a relatively harmless component of wastewater. However, excessive use of toilet paper or flushing of non-biodegradable materials (e.g., wipes, sanitary products) can contribute to:
Toilet paper is made primarily from pulp fibers. Manufacturers use shorter fibers compared to other paper products. Because the fibers are short, they do not interlock as tightly, making it easier for water to penetrate and separate them.