I have three cartridges and never use them, they were a waste of my money. I always run the wheel through my colored ink or Versa Mark pad and then run it over the card front. Since I never do anything bigger than a card it works fine for me.
A tip if you haven't worked with wheels is to find the seam and turn it so the seam is just behind your starting point. On some wheels it doesn't matter but on others it shows and I just don't care to see where the seam started. Out of my SU wheels the only one I notice it on is the Heart of Africa and it's obvious. If you look close under the image you'll see the gap in the card I linked between the yellow and blue sections. I figured it out
after I did this card!
Heart of Africa wheel