i would only use it, if you have a lot of small patches all over the area and weren't able to adjust the shading perfectly. but be careful not to overuse it, otherwise the lines will become blurry.
if you want some examples, i made some chapters at my redrawing tutorial ch 3 / 4 and ch 13 about...
Chapter 15 - Spiky Bubbles
it's really hard to redraw something like that
the first problem is the spotty lines
and fading out
if you want to redraw that "perfect", the only way is at raw size.
the following is a close enough redraw at final size.
first redraw the background.
Chapter 2 - speedlines over patterns
here we have a typical example of the problem:
and here how it looks like after we are done:
as always here's the psd file: rd_demo_2.psd
always with such a redraw, i paint everything white what i won't need any longer. normally i always draw...
Original Post here
speedlines over patterns
How to make your own patterns
dealing with different shades of patterns
typical shoujo pattern
Fixing Patterns after redrawing