Checkerboard shading
A checkerboard shading effect is easily achieved with conditional formatting as shown below. The conditional formatting dialog is invoked with Format - Conditional Formatting
Please review earlier articles on conditional formatting here , here and here.
When the condition (formula) evaluates to true, then the specified style is applied to the cell. We have seen this before. ISODD is a boolean function so is ideal in this situation.

The resulting pattern…
