Laser engraving with font



Just wondering if someone can help and point me in the right direction

When laser engraving with different fonts, if I choose no fill it shows the outline of the letters but with lines in the middle where the letters join but if I choose to fill it inverts them and fills in around it

Just want to no how do I fill the letters without the part where the laser misses!

I hope you understand, I have uploaded some photos so someone can help