Thank you for writing.
The negative number format is the same as in a standard Microsoft NumericUpDown. We are using the standard .NET means for handling Right-To-Left formats. The difference between the way RadGridView displays the value and how the print looks like comes from the fact the the printing logic does not set a StringFormat.FormatFlag when the cell is printed. I have logged this in our Public Issue Tracking System - PITS
. You can track the progress of this issue, subscribe for status changes and add your vote/comment to it on the following link - PITS Issue.
Until this issue is resolved you can use the workaround you have found yourself.
I have also updated your Telerik Points
for bringing this issue to our attention.
Should you have further questions, I would be glad to help.