"He who marches out of step hears another drum." ~ Ken Kesey
First a comment on ink flow/stirring.All Inks are tested in the lab before being released to the public. All viscocity testing is done with the ink at 72 degrees fahrenheit. This is why you see proper print characteristics when the ink is warm. That's how it is tested.Now a very quick very very basic breakdown on ink chemistry.Viscocity Buster = PlasticiserCurable reducer = Resin and Plasticiser. No Filler. No thickener.Chino Base, Fashion Soft, etc... = Resin, Plasticiser, some filler for effects, and very little thickening agent like Cabosil (Fumed Silica). They are all a little thicker than standard Curable Reducer.Ink Bases = Resin, Plasticiser, some filler ingredients for rheological/adhesive/opacity/flashing purposes. Thickeners for desired effects/rheology.Finished inks = Resin, Plasticiser, filler ingredients, thickeners, and supporting chemicals based on end use.Quickest way to reduce viscocity of white is by using the most fluid product available. That is plasticiser. But if you over add you end up with extended flash times and/or the potential for not curing.Second quickest way is to add curable reducer. It has no viscocity modifications and will create flow that much faster. Yes, it can extend flash times.3rd option is a lower viscocity base of your personal choice.However, this is screenprinting. We all have our personal opinion on proper flow and print characteristics. If I get my best print characteristics by using curable reducer and someone else gets their best print characteristics by adding the thickest base known to man. Then they are both correct answers.I believe the reason why Alan went with the base in his white is because it improves the screen shear of the ink while also keeping it's viscocity low and rolling just enough. Curable reducer does not change drag/shear qualities of an ink.The short answer on the Street Fighter ink. It's inconsistent. I have been using it for the last year and it..... frustrates me. Sometimes it's "runny" lower visc. Sometimes it's very short bodied and reminds me of old XOLB-158. Most of you will understand that reference. Flash times on the SF are not consistent as well as the opacity. Conclusion, it is a cheap white. A Very Good cheap white. As a result, you learn to work with it, or search for a new white..... like me.My 2 cents.
I'd love to know what makes an ink long bodied and short bodied as well. There isn't (I haven't found one yet so doesn't mean it doesn't exist) a poly ink that I've tried that has a short body to it therefore they are all extrudable and more difficult to work with. They do tend to matte down the fibers and cover really well but a short bodied white is ejectable and therefore shears from the screen with ease and is more desirable when reaching for maximum opacity with one stroke. Whatever makes the poly ink bleed resistant is making the ink long and stringy, that much I do know, but I can't wait for Colin to comment on this.
Quote from: alan802 on November 22, 2013, 09:17:15 AMI'd love to know what makes an ink long bodied and short bodied as well. There isn't (I haven't found one yet so doesn't mean it doesn't exist) a poly ink that I've tried that has a short body to it therefore they are all extrudable and more difficult to work with. They do tend to matte down the fibers and cover really well but a short bodied white is ejectable and therefore shears from the screen with ease and is more desirable when reaching for maximum opacity with one stroke. Whatever makes the poly ink bleed resistant is making the ink long and stringy, that much I do know, but I can't wait for Colin to comment on this.I agree that poly inks are a little harder/slower to move across the screen, but the last fiver of Miami had a little string to it and was, for lack of a better word, creamy? I went down great with one hit, sheered perfectly. This new fiver is a completely different ink and I'm struggling now to add things to it to "fix" it and get through the damn ink. Softee base is going in today and I'm going to do a full drilling top to bottom, there's about 50% left. The drill is going to hate life today.
Wow it sounds like me and you got ink from the same batch. I am almost at the point of shelving it and not using it again, or mixing some poly white into it.
They won't admit it but most (pls) ink companies buy their raw materials from a very large ink company which will remain nameless. Also not discussed in availabity of said raw materials and their consistencies and occaisionally lack thereof. Which (also not talked about) can result in re-formulation.When thats done the ink runs through the usual testing for viscocity, opacity, and other rheological traits. Except, as printers, we pick up on things that they miss. Adding puff to a white is a well known bandaid to make up for weak raw materials for instance.
Quote from: tonypep on November 22, 2013, 10:39:13 AMThey won't admit it but most (pls) ink companies buy their raw materials from a very large ink company which will remain nameless. Also not discussed in availabity of said raw materials and their consistencies and occaisionally lack thereof. Which (also not talked about) can result in re-formulation.When thats done the ink runs through the usual testing for viscocity, opacity, and other rheological traits. Except, as printers, we pick up on things that they miss. Adding puff to a white is a well known bandaid to make up for weak raw materials for instance.Good info as usual Tony. The amount of inks we've used the last year and the fact that so many of them are almost identical in body and opacity makes it easy to believe it's being made from the exact same materials. I'm sure we'd be very surpised with all of the secrets of the ink industry.