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Alternative Processes

Discussion in 'Colour or Not' started by Zou, Jun 8, 2021.

  1. steveandthedogs

    steveandthedogs Well-Known Member

    H2O2 it is, about 2% you can get it as Sterilising Fluid from chemists.

    S
     
  2. Zou

    Zou Well-Known Member

    My understanding is that hydrogen peroxide just speeds up the natural process, it doesn't enhance it? Maybe I'll check the paper again tomorrow to see if contrast has increased but to be honest I think the nature of this kit is cheap and cheerful and it will be an easy to handle formula (only wash in water, no citric acid) with limited capability.
     
  3. steveandthedogs

    steveandthedogs Well-Known Member

    Not according to

    From 9:14 onwards.

    S
     
  4. Zou

    Zou Well-Known Member

    Why can't there just be one set of flipping instructions instead of all this contradictory nonsense!

    Anyhoo, this paper says just rinse in water until it runs clear, which is what I did.
     
  5. steveandthedogs

    steveandthedogs Well-Known Member

    Yep, and then rinse in peroxide, then rinse again.

    S
     
  6. Geren

    Geren Well-Known Member

    You can just rinse in water - and then rinse again in clean water. One of the key things that he's doing is that he's rinsing in running water which means it's not sitting in its own muck. Think shower rather than bath. The bleach solution only really intensifies the colour of the blue - if the detail isn't there I don't believe it will turn up. Maybe a longer exposure was needed?
     
    Zou likes this.
  7. Petrochemist

    Petrochemist Well-Known Member

    Laser printers use heat to fix the toner - so transparencies for them HAVE to be special ones.
     
  8. Petrochemist

    Petrochemist Well-Known Member

    I'm not surer why full spectrum light would be NEEDED, isn't it just that it works with any visible light. UV photons are more energetic than visual ones so should have enough energy to activate any reactions that are triggered by visual light. Sometime UV might imitate unwanted reactions as well but then you'd want light without UV rather than full spectrum...
     
  9. Zou

    Zou Well-Known Member

    My guess - I'm no expert as this thread has reiterated - is that lamps are generally at a fixed wavelength and due to the nature of the light sensitive material in anthotypes, they probably don't react as well to those fixed wavelengths?
     
  10. Geren

    Geren Well-Known Member

    210703-cyanotype-001A.jpg

    210703-cyanotype-001B.jpg

    Here's one I made as a demo for my workshop this morning. The second one has been treated to a hydrogen peroxide rinse and you can see that it has properly intensified the blues. This was done on really shoddy cartridge paper and washed too many times so the surface of hte paper is starting to break up. Although I quite like the effect of that and I think I may try scrunching some paper up after I coat it to see what happens. Also, because I was very aware that my group all have various degrees of mental health issues I wanted to keep this as health and safety conscious as possible so the plant material and sensitised paper were under acetate rather than a glass plate. I think glass would have squished the plant (some weed I found on the beach) more an dthe contact would have been better.

    Photos taken while paper still wet as well so it will change again once it has dried.
     
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  11. Geren

    Geren Well-Known Member

    Yes, I know. And I may have swiped the transparencies from a defunct cupboard at work where they were lying around left by the previous occupants of the building (actually that's a shameful story of public money being wasted but perhaps for another thread. Let's just say that we've not needed to buy a polypocket or a ring binder yet and we've been there four years.) ANyway, I assumed that as the printer at work was a laserjet/photocopier that the transparencies would be suitable for it. And that they would therefore be suitable for my own laserjet printer. I assumed wrong.
     
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  12. Petrochemist

    Petrochemist Well-Known Member

    LEDs (and specialist elemental lamps used in atomic spectroscopy) are at fixed/highly restricted wavelengths my other UV sources (Fluorescent/Deuterium/Xenon lamps all provide a much broader continuum, but physical chemistry has shown that sufficent energy is needed to activate reactions & UV is more energetic than visual - Any UV wavelength will have more energy than any visual wavelength.

    I think it's far more likely that someone tried it with a low intensity UV source & assumed the meant there was no reaction. I suppose it is possible there may a reverse reaction that is activated by UV light, which would make UV a bad choice but then you wouldn't want full spectrum light wanting any UV removed for maximum reaction.
     
    Last edited: Jul 3, 2021

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