Random Card of the Day

As far as the lines go, that comes from scanning at too low a resolution.  I scan everything at 600dpi and then re-size the files down to something more manageable and I never get those patterns on my images anymore.  It comes down to your scanning approach.  If you're just in a hurry to get as many cards scanned as possible, and scan and low quality to avoid adjusting the images later, you will always get lower quality results.

It can also be scanner based. My Epson scanner scans at a lower resolution but has no lines (it also has higher depth perception and can do neons) where the Canon scanner scans higher dpi but puts the lines. It actually picks up foils though usually, where the Epson scans all foils as black, and puts pink lines on refractors/holofoils. (which I why I use more than one scanner)

 Doesnt the system itself make the file sizes much smaller? 

I sampled cards from Billy, Clyde and gb and all were between 16kb and 33kb. (Billy's were the highest of the ones I sampled). Thats really not much of a difference in terms of either HDD space or bandwidth. 

Then I uploaded a card I scanned at 300dpi. I left it at its original size of 756 x 1053. Photoscape says it is 348.6KB. When viewing the properties of the card after uploading its 251x350 and 19.3KB. So it seems the system reduces the file size to where an increased DPI is only going to mean the difference of a few KBs once uploaded. Unless Im missing something. 
 

That said, Ive tried scanning at 600dpi. It took forever on my Epson all in 1. And on the cards I scanned I didnt see much of a difference. But Im  willing to give it a try for any refractors or other cards that give color issues when scanned.