A Grid is usually manually loaded by selecting it from the GridLines menu. If you always want a particular grid to be displayed when a file is loaded, you need to export the grid to a file name that is the same as the file with a .vgrid extension.
For example, to always display a grid with Filename.dat, you need to create a grid file with the name Filename.dat.vgrid.
The .vgrid file needs to be in the same directory as the file being viewed - or in the Default Grid Directory (see below).
Creating a .vgrid File
After you have created a Grid, you can export it by selecting Export from the right-click Grid menu. Note that an exported Grid will not appear on the GridLines menu. If you want the Grid displayed in the GridLines menu, you will also need to Save it.
If you export the Grid to a file named .vgrid (just an extension, with no file name), that Grid will be used for all files in that directory.
Default Grid Directory
You can specify a Default Grid Directory by selecting Default Grid Directory from the GridLines menu. If a .vgrid file does not exist in the current directory, V will also look in this directory.
Note: In order to load grids automatically, you need to enable the Auto-Load Grids option on the GridLines->Options menu.