Notice that a well-inked comic has some extremely dark areas and some areas that are not so very dark. In inking, you vary the darks by the use of inking textures.
There is no variety of texture in the above image, but it does show you how dark that parts of your comic should be.
In the above image, the artist has also used gray paint.
Make your line art more interesting by varying the textures and the range of lights and darks.
©Jacki Kellum August 5, 2016