So I am still very new to the business and have learned alot from you guys. I have been seeing a growing market for these Corr. Signs and have never done them before. I currently have a order of 100 if I can learn the process and several potential big orders to follow. My questions to you guys are:
What screen mesh would you recommend for screen printing them?
What type of ink would you use?
I notice that you air dry them. How long do they have to air dry before you can touch them with smearing them?
Do you print them from top to bottom with the grain or go against it?
Where is a good place to buy these signs with the stands in bulk?
Dry time: at room temp. with a fan going they will dry very fast. By the time you've printed the last signs the first ones will be dry. Make sure you have a rack or some other place for them to go. (you'll need a lot of free surfaces if you don't have a drying rack!)
Print Direction: You can print with the grain or against it. The direction of the 'flute's depends on how you want it to slide onto the stake/stand.
Where to get it: I'm not sure, there's a local sign shop that sends all their coroplast jobs to me and they buy the stock themselves. I've never actually bought it myself. If you Google 'coroplast' you'll get a lot of results.
I agree about the Nazdar Corogloss ink, but you really need the retarder/thinner to add to it at about 10-15% by weight. Makes all the difference in the world.
I print using 230 mesh. I print against the flutes because it's easier (for me) to use a shorter squeegie on a longer stroke than the opposite.
Have all your materials ready to go, 'cause once you start, you've gotta keep printing, 2 to 3 a minute and keep the mesh flooded between signs. Then as soon as you're done, clean the mess up with a good graphic ink wash and take the screens to the sink and wash with your usual ink degradent/wash.
You'll also need some good rubber gloves, and make sure you've got plenty of ventilation, or use a respirator.
230 mesh should work better than 305, i use 195 usually. if you're printing while it's hot (which it's definitely not right now!), it will dry in the screen very quickly, so i've found a coarser mesh works better, by holding more ink in the screen after a flood pass.
also, you need a graphics type printing solvent resistant emulsion or it will break down. i've used ulano qx-1 for years and is great for coro.
nazdar 9700 works good too. much slower drying time, which sometimes has an advantage. you have to use nazbond catalyst with it.
I should have mentioned retarder too. It really does make a big difference. And I've found that if you're getting little 'cob-webs' or strings around the image, or even bubbles in the ink it's usually because the ink is too thick. If you're doing a long run it's not uncommon for the ink to start thickening up as the solvent evaporates from it. I even got bubbles in the ink from using too low of a mesh back when I first started.
Do any of you use an automatic clam-shell type press? I have an ancient Lawson I want to get back to working order. It seems to all be driven by one motor. new ones use motors and pneumatics and...technology...
Corrugated Signs 
