When you want to scale a drawing with a grid (grid system)

[gregn29157636]

When you want to scale a drawing with a grid (grid system), how can you tell the grid you're using is proportional? 

[JJMack]

Photoshop Grids are uniform with some number of sub decisions. So Percentage settings would be relative to canvas and the grid would change with canvas size aspect ratio  

 Guide Line layeout can also be set  the have row colums gutters and margins width height quite customizable. and  youy can save presets.

You can write a Photoshop script that layout proportional guidelines adobe does not supply any.  I have just written script to sub divide documents evenly with different number of subdivisions. You should me able to do the same with action and Presets. When grid divisions are set in percentage. I would think Percentage setting in grids would be relative to width and height and be change automatically by Photoshop should you change a documents canvas size. Guide Lines Layouts  would need to be cleared and some new layout set if  you change a document canvas size for guideline layouts can be quite complex with gutters and margins and other size settings.