When you select multiple faces from the viewport, ABAQUS/CAE highlights all internal and external edges of each face. In addition, grid lines (called isolines) are drawn on each selected face. You can turn off the display of these isolines to enhance the display speed for large models. With isolines turned off, ABAQUS/CAE highlights only the edges of the selected faces.
When you click on the selection options tool , ABAQUS/CAE displays the Options toolbox. Toggle off the Show Isolines on Selected Faces tool
to turn off the display of isolines. This tool is toggled on by default.