Direct-to-paper protective coatings?

[Floydian]

I'd like to experiment at some point with natural shellac diluted in ethanol, as well as with industrial grade water-based polyurethane (wood varnish), to protect paper or canvas prints with pigment inks.

Shellac is UV and dirt resistant - although it doesn't like heat, water, or scratching. It also has a natural gloss finish, and can warm the colours a little or a lot depending on the flake/powder hue - generally from sand to amber tone.

Waterborne polyurethane can offer UV, dirt, and scratch resistance, but doesn't protect from humidity and heat like the solvent-based kind. It can make quite a clear coating as well.

Does anyone have experience with these? Any paper incompatibilities? What is your favourite sealant and technique for your prints?

 

[ccc]

Graffiti artists report that the latest auto clear coats that can be found in spray cans are the best, latest protection for images.

 

[Paul Verizzo]

Your quest stirs vivid memories, even though I can no longer remember many details. Around a dozen years ago I did extensive amateur research on coatings and films. My goal was to prevent my Canon dye images from fading by UV or humidity. This effort was done on Florida's west coat, on the water, with printed images on windows facing SW.

I tried shellac, water and oil based clear coats, window tint films, vinyl laminating, polyurethanes, UV museum glass, and most likely many other thing's I've forgotten. Even Saran Wrap, there were good reason to consider this option. All in the quest to make "archival" prints with dye inks.

My research also included paper types. Instant dry vs. well, not instant.

The biggest "take away" of my dozen's of many hours of effort is that it is really, really hard to have a perfectly even liquid spray or brush on coating. The tiniest imperfections look like boulders.

You've not mentioned what your goal is, whether you are using dye or pigment inks. I can't afford a pigment printer, simple as that. I have many Canon dye prints that have been in my rooms in mostly subdued light for six years. All are well enough to be displayed again in a gallery for the third time in six years.

As a side note, maybe twenty years ago Epson had a clear coat cartridge on a series of their printer. The colors would be laid down, then the clear coat. I've no idea of it's archival qualities, but , damn, seems like a great idea.

These days I don't worry much about these matters. If one has a good JPG, TIF, whatever, if the print fades, just print another.

 

[Ink stained Fingers]

@Floydian , it is not clear what you want to acheive, which inks you use, which type of paper you use with your inquiry.
Let me just give you a tip to experiment with - use hair spray - that's water based polyurethane, that comes in various strenghts, from various different companies , and you can easily apply layers of a different thickness of your coating, and you'll see that sprays of different companies are not all alike.

But do not expect too much a UV protection effect , if fading is your prime concern - start off with OEM inks - dye or pigment, and use PE glossy paper which protects the print from the backside with the PE film against ozone which otherwise can migrate through the paper and accelerate the fading.

 

[Floydian]

Hey, I don't know why everybody's asking me what ink I'm using. It's there - pigment inks - the last two words of the first paragraph. And no, I didn't edit that line.

@ccc
The main drawback with spraying cans, is that you need to get yourself outside every time you want to apply a coat, and the particles dance in the air, no matter if you're wearing a mask or not. I don't really fancy them.

@Paul Verizzo
Nice! No doubt, Florida weather makes for an excellent open laboratory to experiment with. Well, after the printing has been done correctly, I don't mind imperfections like surface unevenness or a hint of colour tinting from the additional coating, I even prefer them to a certain extent. It makes things look a bit organic in a way. But sure, there are defects and defects...

@Ink stained Fingers
Since I'm experimenting, everything goes. The main idea is protection for different kinds of weather, and the only thing that's not going to change is the ink type - again, pigment-based (InkTec PowerChrome K3 with photo BK in particular). Media types may vary, but for mow I'm limited to what the WF-7310 can handle - up to A3+ paper, or 33x120cm long. Also, I was thinking about processing both sides of the paper.

Thanks to this forum, I already have an idea of what to expect with matte or encapsulated inks on various paper surfaces. I'm waiting for the refillable cartridges to arrive (it's going to take a while), but I might do some tests with the OEM starter cartridges before that, knowing that there will be gloss differential due to the matte nature of the 405 BK.

Essentially, I want to reach a compromise between efficiency, convenience, appearance, health, and cost. Yeah, good luck with that! But, anyway, this isn't just about my own preferences, I'd also like to read what other people are doing in regards to protecting their prints, and what worked best for them.

 

[Ink stained Fingers]

I'm using hairspray in a few cases, it's easy and does not require much practice, but since this is out for you air brushing would be as well out for you. All bronzing and gloss differentials go away with such a spray method.

Be aware that the matte pigment inks do not adhere much to glossy surfaces, and the driver will not use the matte black ink as soon as you select a glossy type paper in the driver. Prints w/o a black ink don't look so good but since you are planning to do refill you have the option to use a photo pigment black instead and select a matte/inkjet paper but print on glossy paper . So you have some options with the black inks. You can print with the photo black onto matte type papers - the difference to a print with a matte black ink onto a matte paper is a slightly weaker black level - that's sometimes not even visible if you compare prints with both black inks , it depends very much on the paper you are using.

Ink types - it wouldn't be the first time that the scope widens during the course of the discussion

 

[Paul Verizzo]

Graffiti artists report that the latest auto clear coats that can be found in spray cans are the best, latest protection for images.

Months later........those are just lacquer. Nothing special. OTOH, lacquers don't degrade in sunlight so there is that. Otherwise every GM car from the 1930's to about 1980's would have degraded. True, the pigments would fade, but not the carrier.

(Starting in the 1970's, car companies went to a base coat/clear coat system. The base coat provides the pigment, the clear coat protects it. The clear coat is a polyurethane.)

 

[Paul Verizzo]

@Floydian , it is not clear what you want to acheive, which inks you use, which type of paper you use with your inquiry.
Let me just give you a tip to experiment with - use hair spray - that's water based polyurethane, that comes in various strenghts, from various different companies , and you can easily apply layers of a different thickness of your coating, and you'll see that sprays of different companies are not all alike.

But do not expect too much a UV protection effect , if fading is your prime concern - start off with OEM inks - dye or pigment, and use PE glossy paper which protects the print from the backside with the PE film against ozone which otherwise can migrate through the paper and accelerate the fading.

Months later......More complicated than that: https://en.wikipedia.org/wiki/Hair_spray