I looked on the forum to see if I could find the answer but was confused. My dark grid lines are showing every ten lines on PC Stitch but when I export as pdf to print the grid lines do not show on printed document. Can someone please explain what settings I should change. I have grey setting for the lines normal width at 1 and black bold set at 5.
You say you see the darker gridlines. What do you see with a print preview. If you don't see them there, you've got a setting missing and they won't print even under normal circumstances, not just a PDF.
If you see them on a preview but not as a PDF, try a normal print. It may be something as the PDF is created.