You will need: white glossy card stock, 2 ink refill colors, an optional metallic ink refill, cotton ball and rubbing alcohol.
Roll your cotton ball or pad into a soft ball, adding 2/3 drops of your first Ink Refill color to the resultant ball, then do the same with the second ink refill color.
Add some rubbing alcohol directly onto the cotton ball and dab the ball all over the card stock until it is covered.
If one color does not show that well, add more of it to another cotton ball as above, then apply over the card stock.
Once complete you'll have a perfect marble effect card slip for your Scrapbook.