Digital BW, The Print

I'm not a chemist, but I do know an industrial chemist and can converse easily with him about chemistry.

Here's a curious one for you all, I received some left over concrete sealer, which is 70% Xylene solvent acrylic lacquer.

The high quantity of solvent is to aid penetration into the pores of the concrete to seal it, rather than just a top coat that can wear exposing the pores.

Breathing apparatus and skin protection is essential with it's use.

Xylene used to be the solvent in some permanent markers, some now specify Xylene free.

It's by far the best timber lacquer I have used, but is difficult to attain a perfect finish spraying or brushing.
It dries to a full gloss finish on timber.
It also lists UV protection as one of it's qualities.
I haven't done a test to check for yellowing over time.

That gives some background

I tried spraying it onto a print to see if the Xylene solvent would disturb or react with the ink, in this case dye.
No issues whatsoever.

I went so far as to saturate one section of the print, which was on Arches cold press 300GSM, till the lacquer was visible through the back of the paper.
Again no issues.

At the time I didn't have a spectrometer to measure if there was any discernable density change, but I may be able to do some tests on a greyscale separation early next year.

Now the good part, it's $70Aud for 20 litres. That's a lot to use, actually too much, but if you do the garden path or driveway, keep some spare to try.
However I'd also suggest auto lacquer, which is used for scratch and UV protection over metallic and pearl finishes, would be an excellent choice for some tests.

A slight variation on clear auto lacquer has been used in the surfboard industry for decades. It's a clear final coat with a matte finish, which is just auto finish with a gloss inhibitor = matte finish.

Clear Auto finishes are usually available in pressure packs for those without spray equipment. Also some auto paint suppliers can load individual pressure packs for anyone after a gloss inhibited, matte finish.

If you really want to know the chemical composition of what you're currently using - locate the MSDS (material data safety sheet). Sometimes individual elements are just listed by CAS# in an attempt at concealment. Just research the listed CAS# instead.

peace out

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Myron Gochnauer <goch@...> wrote:
>
> Do we have any chemists in the group?  
> 
> The photographic "fixatives" may very well be, at most, slight tweaks on common coatings.
> 
> I have often wondered whether there are any meaningful chemical differences between a pricey gloss or matte "art" varnish and a top quality product made for floors or furniture.  There are very few types of clear coatings, and they have been well understood for years.  My wild guess is that there is not a large enough "art market" to justify wholly distinct formulas and manufacturing, although I would imagine that manufacturers can easily tweak formula runs for special purposes.
> 
> Myron
>