I have a file where when I change it from a .ai to pdf I lose part of the file.

[Nin5FAA]

I have a picture where when I save it from a .ai file to a pdf file I lose components of the file. 

I have checked to make sure that the 'print' part of the layer is on. The odd thing is is that the dots come up when I save the .ai as a pdf, and they dots and the lines are integrated into the same layer, so theoretically they should be doing the same thing when I save the file. 

Any help would be very much appreciated!

[SJRiegel · Accepted solution]

Digging into this file, the lines all have no stroke width and no stroke color. They only have a fill color, that is why they are not showing.