I just received a batch of photopolymer plates from a nearby platemaker. The plates look good, but I was charged for an empty half-inch margin on either side (but not the top and bottom) of my designs. It adds up to about $8 of unwanted empty space. Odder still, the plate I received is larger than the total of square inches that I was charged for, so I’m paying for some empty space, but not all of the empty space I got. My files didn’t have any extra margins at all.
This sounds normal. There needs to be margin in between your designs and the edge of the plate. Otherwise, there will be light leaks from the side of the negatives which would affect the designs on the edge of your plate. I would have to see your plate to be sure though.
My photopolymer platemaker tells me to set the width of my file to 13″ and fill it up from there, because no matter what the plate is going to come out on that width. I rotate and cram in as much as I can to set the plate up as short as I can using that width, and have never bothered with more than a few pixels of margin (enough so I can visibly see that the image is not touching the edge). Never had a problem, and never been overcharged, but I do need to keep some items on hand to fill in the space when it’s there, because I’m paying for it anyway! Good luck!
In the past I’ve also ganged up all my designs before sending out the file. This time, though, I only had 4 really simple rectangular pieces, and I really wanted to get started printing rather than fiddling around with designs, so I sent them off individually.
I was so anxious to get started that I didn’t include a matching design for the packaging. Just spent about 48 hours trying to come up with something nice in metal type. No more complaining about photopolymer…