Australia's Science Forum

Who can tell me about this stuff?

It seems out supply is old and may not be doing what it is supposed to be doing....i just found an unopened batch from 2008 - awaiting results...

thanks guys!

I have never heard of it - what do you use it for?

Never heard of it either.
Lada

something to do with printing google says so
LOL
sorry it is monday and i am trying to stay away form coffee - it seems to be effecting me

LOL all of you - and it is supposed to do soemthing whwn exposed to light~

Diazo paper will darken when exposed to sunlight. you can put nicely shaped objects on in and then place in sunlight. It doesnt keep all that long may be a year.

ok, so out to the quad i go.....
hope its not expensive....willhave to replace the packet i think..

I have looked it up in the Serrata catalogue, it is also called ammonia paper and in the 2006 price is $49.95 for 125 A4 sheets...so not cheap at all.

I vaguely remember doing something with 'ammonia paper' at uni, we all designed something on the piece of paper and then out it in large jars in the sun...and what we wrote or designed was then visible...

Hi
I have not used it in years but yes you put out in the sun with something a shap maybe and it changes colour and leaves the image on the paper just like an Xray

They use it in drawing offices to copy plans
Step 1 put drawing on transparent paper on top of yellow side of Diazo paper
Step 2 Expose to UV light
Step 3 expose paper to Ammonia fumes or pass through ammonium hydroxide solution
Then you have print from plan

Drat! I am too late again! I have only just read this thread, but the answer has already been revealed, thus dashing my hopes of astounding you all with my vast knowledge!!

I can remember using Diazo paper back in the 80's to "photograph" magnetic field lines. We put the diazo paper over a couple of bar magnets, and sprinkled iron filings on the top to get a nice field pattern, then exposed it to sunlight (without disturbing the filings- now that was tricky!) then rolled it up in a big 1 or 2 Litre measuring cylinder with a few mL of ammonia in the bottom and a book over the top to keep the fumes in. It made a pretty blue impression of the field lines. It was fun at the time, but I have not seen the stuff in 25 years!

Oh well, mystery solved by Ocker and Noona!

Cheers
Ian

Ian,
I recognise your astounding knowledge and expertise

Ian
You are still the best and Rob

Ian, I salute you & your enormous contribution to all knowledgable things lab techish... (& other things I'm sure!)...

I knew this as architects paper... for the reasons stated above by Noona & Ocker & Ian....& your other brainiacs

In my past life I worked at the local paper mill and we made this paper. My job was to make the diazo solutions to coat the paper for the print testing. It was quite messy and trichloroethane was the solvent for cleaning. Those were the days.......
In recent times I was asked for paper "that faded"... I rang local architects and made my requests. The receptionists had no idea what I was talking about and the architects laughed. They hadn't heard of the diazo paper for years. Everything is generated on the computer. (How to feel prehistoric).
However, an alternative of sorts is the smooth shiny rolls of paper that is used by cash registers. Those receipts always fade. Can be purchased at OfficeWorks or stationery suppliers.
Good luck
Rita

Good alternative Rita,
I always wonder what will happen if a tax audit happens to me and I have diligently kept all my receipts. In a few years time they aren't going to show anything because they fade away to nothing. Maybe its a way to legitimately do a tax dodge.

I'm absolutely certain ProfBunsen sells something that one can paint onto paper, making it light sensitive. I made up a stack a couple of years ago. The kids place objects, e.g. keys, paperclips, paper cut-outs, onto the paper and leave it in the sun for a while. The you "develop" it by rinsing it in water. The picture seems to disappear and you think "Oh NO!" but then it reappears, and it is permanent.

Teacher wanted to do the Iron filings magnet thing . Our Diazo paper is dated 1980 . Its all gone off .

Interested in the Shopper docket paper Rita . How do you use it ? I belief it is thermal sensitive paper but it does fade in the sun .
So I'm wondering should we heat it to make it go dark and then expose it to the sun ( with the iron filings etc on it ) to make the exposed bits fade.

Hmmm I feel an experiment coming up .

It was used to copy plans on transparent paper exposed to light then lightly spray with ammonia solution to set image but with modern plotters I think it would be obselet