Last Update: 4/25/2023
In Origin, following font types can not be shown as bolded if the labels rotate 90 or 270 degree. If your Y axis title is set as the font, it can not be shown as bolded.
If you meet the problem, we have following suggestions
Method 1: Change the Font Type
Following font types supports bold for vertical labels
Method 2: Change the Label Rotate Angle
We can set the rotate angle of the label to be 89 to work around the problem