How to create scan lines (Defining a pattern)

[bigsharn]

You've actually done the classic mistake, if you use that the scanlines tend to be more spaced out on the picture

Using the patterns below gets you some nicer effects (B = black square, W = white square, T = transparent square)

Diagonals:
TBW
BWT
WTB

The other way:
WTB
BWT
TBW

Vertical:
BTW
BTW
BTW

Horizontal:
WTB
WTB
WTB

This way you can use lighten or darken depending on which you need for the image, and it saves you faffing about with inverting the colours