How can I easily format all cell borders in a sheet with existing data

[sciurus]

Hi
In Calc if I select one cell, and go to Format – Cells – Borders, I can set the side/s where I want a border, the style, the line thickness, and the colour. That’s OK.
If I select a block of cells the setting applies to the block borders, not the border of each cell inside the block which is what I want to set.
The best way I have been able to find is to select column A and set the left edge, set column B and set the left edge and repeat for each column in use, then select row 1 and set the top edge, set row 2 and set the top edge and repeat for each row in use. Very tedious – surely there must be an easier way?
I would have thought that there would be line borders of some sort as a default, rather than none.

I’m very new to LibreOffice, so apologies if there is an obvious answer.

[Jez]

Select the cells, go into Format Cells | Borders, and click in the middle of the “User-defined” square. A black “cross” should appear in there. If you OK that you will see it’s added lines between all the cells.

[ianbattison]

Select the cells. Press CTRL +1. Select the BORDERS tab from the list across the top. Where it says LINE ARRANGEMENT, it gives a few icons as PRESETS. Select the one with a black border and the cross in the middle. (Should be the 4th from the left). Click OK. This will change the border and the inner lines of the cells you have selected. You can also change the styles etc at this point. Hope this helps.

[sciurus]

Both answers make the solution clear thank you both. I had misinterpreted the User Defined square. This was my first post so not sure what to do to show the question answered OK.