I have sharpened and done some testing on the Prismacolor Col-Erase.
Here it is, the testing sheet of the Prismacolor Col-Erase. First of all, I wonder how much of a difference there is between the color Light Blue and Non-Photo Blue, hoping that the Light Blue could produce the same non-photo effect.
On the right, I tested their erasibility. The right stripe is just the first swipe of erasing. In a way, it makes a good lifting. I used a lot of strength and rub the paper at least ten times for the left stripe. I am not quite satisfied to the shades remains. Obviously, the more indented outline is even harder to erase. By using such strength to rub, the paper texture most probably is ruined. However, I believe that it would be erased to a clean white if the layer of color is very light.
In conclusion, the main reason I buy the Col-Erase is that I want a real erasable color pencil. Col-Erase had performed much better than most colour pencil in that perspective. But, I am still not satisfied.
Note : I am aware about Prismacolor quality issues, reading it from the internet. This package I bought have off centre color core.
