Getting rid of those seams is sooo easy! Trust me on this. Just use a #11 blade from you r Xacto set and gently scrape away the seam line. This will leave a nasty looking but relatively smooth scratch on you canopy. Then, use a polishing kit that includes 3200, 3600, 4000, 6000, 8000 and 12000 grit sanding cloths or pads. Use them in that order and before you know it the canopy will be very clear! Just be careful with the 3200 and 3600 so that you don't polish away the canopy frame details too much.
Now at this point you can dip it in Future if you want. Check out YouTube for some vids on how to do that.
But...I don't dip any Future any more. I use the Novus polish system to get canopies just as clear. Novus is just a polishing paste meant for clear plastic and acrylics. I use a Dremel tool to apply the Novus. I can set down one of the Novus canopies next to a Futured canopy and can't tell the difference!