Yes, Mary, you are just like me. I remembered the paper spot test from my days in electronics kindergarten so I tried googling it up and found quite a good bit of information on it. It was called sulfur acetate paper. Here is just one: https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/test-sulfur-acetate-paper.html -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Mary Davis Sent: Monday, January 28, 2019 1:32 PM To: [log in to unmask] Subject: Re: [TN] Recommendation for Sulfur Spot Tests I can't give you anything but a vague memory. It is my memory that decades ago glass slides with a vapor deposited silver mirror coating were used to test paper packaging materials for the presence of sulfur. Sulfur caused the silver mirror to turn black. Sorry I don't have any more details. Mary Davis, Retired Materials & Process Engineer -----Original Message----- From: TechNet <[log in to unmask]> On Behalf Of Richard Kraszewski Sent: Monday, January 28, 2019 10:30 AM To: [log in to unmask] Subject: [TN] Recommendation for Sulfur Spot Tests Anyone aware of a good spot test to quickly check for sulfur (sulphur) which they are willing to share?? Currently, using the iodine-azide method from the classic Organic Spot Test book by Feigl with limited success. Hoping some else could recommend some other. Rich Kraszewski Senior Staff Process Engineer * * * * * * * * CONFIDENTIALITY NOTICE * * * * * * * * This e-mail and any attachments are confidential from Plexus Corp. and may contain information which is privileged, confidential, and/or protected by non-disclosure agreements. They are intended solely for the use of the named addressee(s). . Any unauthorized use or disclosure may be unlawful. If you are not a named addressee, you must not use, disclose, retain or reproduce all or any part of the information contained in this e-mail or any attachments If you have received this transmission in error, please destroy it and notify us immediately by return e-mail or by calling + 1 888 208 9005.