Create straight dotted lines when painting with any brush in Elements using the Dynamics option
Create these by simply using a brush. Choose any hard brush (the standard round and square brushes are good for this) and choose the colour for your line via the Foreground swatch.
Click on the Brush Dynamics icon in the Options Bar and adjust the Spacing slider.
The greater the Spacing value, the further apart your dots will be spaced. To draw straight dotted lines, just hold down the Shift key and paint.