U of S | Mailing List Archive | alt-photo-process-l | Re: Measuring Bloom?

Re: Measuring Bloom?



http://en.wikipedia.org/wiki/Bloom_(test)

A really significant information is "how much water the gelatin will
absorb?" (not it's strenght) and that can be tested by doing something
like below:

Prepare 10% solution of the gelatin, pour it on impermeable media, let it
dry thoroughly, trim the non-coated parts of the sheet (use a frame while
pouring gelatin, in order to have a regular shaped coating area - easier
to trim), weight the dry sheet, soak in cold water for at least an hour,
drain thoroughly, weight the soaked sheet. The weight difference will
indicate how much water was absorbed by a given amnt. of gelatin, since
you know how much gelatin you poured on the media... If you do this with a
relatively large coating area and volume, you'll have a pretty correct
figure.

If I'm not mistaking, higher bloom gelatins are able to absorb more water
compared lower bloom gelatins.

Regards,
Loris.


6 Mayıs 2009, Çarşamba, 9:12 am tarihinde, Jacek Gonsalves yazmış:
> Hi all,
>
> Was wondering if there was a way to measure bloom of a certain type of
> Gelatin?
>
> Cheers
> Jacek
>
>