http://www.youtube.com/watch?v=OjobQb_rLps#t=28m30s

I tried oil pastels, but it doesn't stick onto the card

Lipstick?

Looks like he wrote with a pen. Write in white gel ink or some other type of pen (you will need to experiment) 1st then stamp over it.

You could just put sharpie on your finger and then roll it on the card. Just don't let it dry before your roll.

The image was of a heart finger print that then had a numeral added in.

If you have photoshop, make a print of your thumb. Change it to look like a heart. Add the number you want.
Have a stamp or transfer image made of the thumb print heart.

You may also be able to find a thumb print on line that you can work with.

Just get a blank faced deck, wipe it over withacetone to het rid of the sheen you can then print directly on the card with your inkjet printer.

What is the gaff? I keep getting an error on the YouTube link.

A card with a center heart pip that looks like a finger print. Within the heart is the numeral 8.

To be honest, David spends a lot of money to get his gaffs made and I don't think its respctful to steal his material, its not for sale for a reason.

Just come up with something unique and get it printed. But, I know how much time and money David puts into getting his custom gaffs, and I don't think he would be happy people are knocking them off. The 'big' magicians avoid magicians because a this very reason, hence why Copperfield will pull certain people off stage if they get selected for a specefic illusion, why other artis will have magicians removed from crowds when filming..Its a shame really.

I don't mean to come off on this kind of rant, and normally never do, but Its just unfair to the creators and performers who paid for the rights to the effects.

SIX nailed it.

It isn't yours, don't be a thief.

Simple.

@pillowman,
Let Blaine's video be an inspiration rather than a heist.

There are plenty of effects that are commercially available that end with a personalized gaff. Blaine centered on one. Be creative and go for another. Make it work and it's yours.

I agree with others about making a different kind of gaff of your own rather than copying Blaine's. That said, this idea about using your printer is handier than you'd think. Many possibilities if you're willing to spend time making gaffs. Funny, but this topic could either go in 'gaffed and funky' OR 'the workshop'! btw Pillowman, welcome to the Café! Lynn