Students in our food safe rubber stamping classes always worry about making a mistake. But there really is no reason to worry... this is the only craft where you can eat your mistakes!
Seriously, I always tell my students that an artist is not someone who never makes mistakes. It's someone who knows how to hide their accidents!
Any number of things can go wrong with inexperienced stampers or bakers... we get both kinds in our class...
For bakers, they are not used to coating rubber stamps with ink and aren't used to tamping the stamp on a pad, checking it for good coverage and then stamping. For those folks, we recommend a foam coated rubber brayer to get an even coat of ink on the food safe stamp. And we train them to ink immediately before stamping.
Stampers have no issues with the coating the stamp fully with ink but often are unaware of pastry tools that aid the process such as a fondant smoother. This piece of plastic makes the fondant oh so soft and it will take the ink much more readily.
Still, there can be mistakes. Waiting too long after inking to stamp; not pressing down with even, gentle pressure; dropping the stamp on the fondant...these can all lead to mis-prints. There is little that can be done with too much ink... simply cut out and eat or trash.
But for too little, it's easy to fix. See the area on the sunflower where it's too light?
I take a wet, thin sable brush and drag it through the dry ink on the lid of my stamp pad. I twist as I load the brush to bring the tip to a fine point.
Then I just paint in the missing details with the stamp pad black on my brush. If you are not comfortable painting, you can use a food writer in black.