[Inkscape-user] Text un-bolds after saving as pdf via Cairo?

Hello all, this is my first post so apologies for any bad etiquette! I have been using Inkscape to crop pdf's of graphs for a report I'm writing. This involves importing the A4 pdf page, selecting the graph or figure and then fitting the document size to the selection. I then re-save as a pdf via Cairo, which has been working really well! Nice, sharp correctly sized graphs. However, I've noticed that bold text (axis titles) un-bolds after saving, any ideas on how to stop this?

I've tried importing at high precision, but no luck. Also there's a drop down box that specifies how text it handled, but I only have the option to "import as text". Thanks in advance!

Alex