I am in a sort of jam. I had been using ulano QX-1 and I still have a couple quarts left, but I can't seem to get the detail like I can with the poly plus. Or at least it seems to be easier with the kiwo. My issue is that I got a quart sample from midwest and have since fallen in love with an emulsion that only comes in gallons or larger and has a pot life of 4-6 weeks. I think that I might have gone through a gallon in the last two to three months of three different emulsions, but I am not sure that I could say that I would go through a gallon of solvent only emulsion in a month and a half.
I just got some TW 11000 series for free and it seems ok, I accidentally let some dry on a chrome spatula and I couldn't pressure wash it off! A little too flat, but I can't complain.
I just took a look at my invoices and it looks like I got the poly plus s sample exactly two months ago and I sensitized it the same day. I have kept it in the refrigerator for the most part, so that might help?I've got more room in the shop fridge for another gallon if it would extend the pot life. I know that I can buy it in quarts on line, but I would rather go through midwest and I would save about a third of the cost, gallon for gallon (in quarts).
This is why I just fell in love with the poly plus, I did an exposure test with a 1kW metal halide on 110 mesh, coated 2x2 round edge as per the manufacturer suggestion. IMG_3513 by StuJohnston, on Flickr
I tried the same with the ulano and it got close but most of the counters in the 4pt type got blown out. As you can tell, the stuff to the right is overexposed due to the nd filter under the transparency. What really surprised me was how sharp the print was! Though it let a little too much ink through for obvious reasons, but it feels sort of embossed. I will be running another test today to compare the emulsions on 305 mesh. I suspect that the ulano will be better on higher mesh, but being able to get fine detail on 110 is really neat.
A related question is, is there a solvent emulsion that will perform like the poly plus S that has a longer pot life?
Oh yeah, is there a major difference between the dyed and undyed poly plus s?
Alright lungs, here are my best answers to a few of your questions:
I usually expect a month out of diazo sensitized emulsion but it can certainly go longer. You want quarts at the gallon price? Get the gallon and parse out the diazo power on a gram scale to mix each quart at a time. If you go with a supplier that is aware of the location of their own buttholes (unlike Midwest. no offense, just my experience) they can probably hook you up with quart-sized diazo bottles with your gallon but the scale and carefully measure H20 will work fine. Use those black vapor-lock containers to divide the emulsion out.
You get detail with diazo-sensitized emulsions because they have a lot of latitude unlike pure photopolymers which have very little forgiveness in exposure times comparitively. If you really dial a photopolymer in you can get very close to what a diazo can hold though and you'll get your long shelf life.
The dye in the emulsion blocks light scatter, which prevents undercutting and yields better detail but is harder to register. Most undyed emlusions still come with some dye that you add in at yer preferred level.
If you do settle on the poly plus s check out the "Z", that stuff is slicker 'n all get out. Literally, it's a low rz recipe and the squeegee just glides right across it.
The TW 1000 series is a flat series. What do you want, satin? eggshell? You could probably mix with some 2000 series. We've used only 5500 so far so I'm talking out my ass here.
I can do the gram scale, which would possibly allow a year on the poly plus. Unfortunately, midwest is the only brick and mortar around here, as far as I know. I do already have at least four empty quart containers, though I should only need one and the vapor lock poly plus will be empty by today/next week unfortunately. As for the measured diazo, do I measure the powder, or syrup I don't know, and the water separately? If so, that might be problematic for me.
I don't mind opaque emulsion, I register with a transparency larger than the substrate. The latitude was pretty obvious come to think of it, allow of the stencil washed out pretty well with the kiwo, at least through the time that I exposed it, but the ulano washed out all the emulsion in one end and didn't wash out at all on the 1x side!
I will try to get a sample of the 'z' next time I get to midwest.
I just checked the e-store and the description for the poly plus Z says 'freezable'. Does that mean I can throw it in the freezer? Or is it a reference to making a permanent stencil? I looked at the tech sheet and didn't see any reference to freezing.
Regarding the 11000 inks, I emailed a salesperson from TW as the nearest suppliers are in seattle and california. I live in oregon, so no go. Anyhow, I was told that they will mix gloss if I request it, same price. I imagine that means high gloss, but I will ask before I order if I can get different levels of gloss. I need to print more with them before I make a decision. The other thing is that even though the msds doesn't mention a respirator, I wear one anyway. I can't stand the smell!
Come to think of it, I might be able to get some smaller diazo bottles from midwest, they have been really generous with me so far. If fact they are quite sample happy, some of the stuff that I intended to buy, they have given me the sample anyway!
Thanks for all the advice! I appreciate that you took the time to slog through my wall of text.
Last edited by StuJohnston; 08-05-2011 at 08:26 AM.