Platinum coating and black spots

When coating paper with platinum/palladium (using a glass rod);

small, black specks often appear on the surface. Does anyone know the

cause?

It can be iron particles left from the scissors you cut the paper or your tap water has iron particles. You should mix all your chemicals with distilled water and cut your paper with a ceramic knife.

Jacques

Are you cutting your paper with a guillotine, rotary or scissors? Does this happen all the time or just some times? what do you use to stir your chemicals? do you buy the solutions made or do you make them yourself?

It is most likely your cutter as it was mentioned before, I doubt it is the water unless you have terrible water, I mix all my chemicals with tap water (and this is mexican water) and have not seen any difference than when I mixed with destilled water. So unless you can see chunks of rust in the water or it has a reddish color I doubt it is this, but it is definitly iron contamination.

Hi.

Some of your metal may have come out of solution. Are you warming the Pt/Pd before applying?

Peter