Actually, I think that expanding a subject beyond a narrow interpretation of an original post is an excellent way to expand the overall understanding of the original post.
Gerald, rather than simply pointing out that "...it is important to distinguish..." perhaps you could elaborate with details. I know that MDR, Jason, and I understand the distinction, but perhaps you could educate others who might read this.
If you're looking for a hardener to replace chrome alum, glutaraldehyde is superb. It is often used as a sterilant by tattoo artists. 1 ml of a 2.5% solution will thoroughly harden 10 grams of gelatin (i.e. 100 ml of 10% gelatin solution).
Originally Posted by MDR
Thank you for the tip. I currently use chrome alum from old crystal growing kits that I bought on Ebay but will look into Glutaralhyde.