adjust description

docs/source/ReadInData.rst

@@ -30,7 +30,7 @@ Here, each solver refers to a single timestep of the timelapse series (stack rec
 
 
 Next, we can read in the 3D arrays containing the coordinates, forces, and deformations either at a single time step (top; A) or all time steps at once (bottom; B).
-Since we are only interested in the forces generated by the cells, we use the regularisation_mask to ignore the areas where the algorithm places the material balancing forces at the stack borders.
+Since we are only interested in the forces generated by the cells, we use a mask (regularisation_mask) to ignore the areas where the algorithm places the material balancing forces at the stack borders.
 
 .. code-block:: python