Photographing petrolem jelly on an object

[Donna]

We have a petroleum jelly jar that contains impressions on the outside of the jar. These impresssions are partially latent and partially patent prints from the jelly. The item was superglued and processed with MBD. Upon viewing with an alternate light source, the latent portion luminesces and the patent portion does not respond to the chemical or the light. We would like to hear from anyone who experienced a similiar situation and have been able to preserve and photograph a smiliar situation satisfactorily.

[Michele Triplett]

Donna,

I haven't had a chance to try this chemical myself because we just got it in our lab, but maybe Sudan Black will work. Here's what it says from the BVDA website:

Sudan Black is a non-fluorescing blue-black dye solution in aqueous ethanol. Apart from staining of cyanoacrylate, it is used for direct staining of fingerprints. The method is not very sensitive, but can be successful on contaminated objects: greasy objects, soda cans with dried residue of the contents.

If you try it on some test items and it works, let me know.

Michele
michele.triplett@metrokc.gov

[Guest]

Donna,

Have you experimented with doing a double-exposure on one frame of film? Take one of the latent illuminated with the MBD and another, on the same frame of film, of the patent print.

[Steve Everist]

Whoops,
I forgot to log in regarding the double exposure.

I haven't tried anything like this with a combination of ALS and ambient lighting, but I've done it with a constant lighting condition and different filters for the same object.

[guest]

If the surface is flat and reflective, direct reflective lighting should work wonderful. This records the difference in light from the absobtion of the jelly and the reflection of the jar.

[MGaines]

During my training with Sudan Black my coach planted prints in Vaseline, and the Sudan Black brought up the prints wonderfully. If the double-exposure doesn't give you good results I think it might be worth your time to give Sudan Black a try. Our agency suggests Sudan Black for all "grease" prints.

[Guest]

This sounds like an interesting project. I don't suppose you are in southern California? If so, I'd like to work with you on some techniques for photographing this.

George Reis
Imaging Forensics