Fill stroke vs flood stroke

[3Deep]

Ok guys had a little time today to mess around, Alan had sent me an email awhile back with some great info on getting a nice one stroke print with white ink.  I will have to say I've use some of that info and have gotten myself some nicer softer prints and productions times a little faster, but my question is fill strokes vs flood strokes, which do you use on your auto?  Once I saw a vid it kinda makes sense to do a hard fill stroke then your print stroke needs very little pressure and the ink is laid on top of the shirt instead of down in the fabric.  My job here is to keep getting better at my craft and I'll say thanks to you knuckle heads I've really got better at it instead of just sitting back cuz I'm making a few $.  So who out here is doing a fill stroke and getting better prints or what's your take on this. Oh this also is 90% about printing white ink in 1 stroke to cover.

Darryl

[mimosatexas]

I personally don't believe in a one stroke white on cotton and blends, maybe on some polys, but where there are fibers, there is a need to print flash print for 100% opacity (or just use discharge when possible ).  I am no expert, but I have always been told and found it true that with plastisol you do a hard fill and the print stroke sheers what filled the stencil onto the shirt, since the idea is to lay on top, not in the fibers.  With waterbased you flood (no stencil visible) then mash the ink through the stencil into the fibers.  This is a basic explanation, I'm sure others can speak more technically about it, especially related to autos and the different angle and pressure settings.

[Gilligan]

I personally don't believe in a one stroke white on cotton and blends, maybe on some polys, but where there are fibers, there is a need to print flash print for 100% opacity (or just use discharge when possible ).

You DEFINITELY need to go to Alan's shop!

[dirkdiggler]

No fill stroke here, I hate them.  Only flood strokes.  Fill strokes break down emulsion and wears out mesh.  Just my 2 cents.

[prozyan]

No fill stroke here, I hate them.  Only flood strokes.  Fill strokes break down emulsion and wears out mesh.  Just my 2 cents.

Same here, just flood the screen.  I don't look to fill the stencil on the flood stroke at all.

[starchild]

Since whites are resistant to any kind of pressure (They uh.. tense up.. when the squeegee pushes them, they push back) it stands to reason pre filling the mesh openings will give the white inks less distance to travel before they touch the garment.. This resistive character is the reason for less squeegee pressure for whites. You might as well throw in thinner threads (fabric thickness is relevant) and wider openings so that the white cooperate more. Oh and stand your blades up so that you're only dealing with one unit of mesh opening at a time- This will prevent the ink from thinning and separating the pigments from the liquid which contains it- the liquids will just soak into the shirt and the pigments will be applied unevenly on the garment giving you that less than desirable opacity. But it really is just choosing some quality inks to work with.

Zoo mentioned in an older post that he bought a gallon of white that felt 10X heavier than a white he was using- Damn that's some good white

[ZooCity]

That sounds like it was in reference to the WFX PC White which is not a printable ink but a pigment base and yes, it feels like a bucket of mercury compared to a finished ink. 

The rules here for plastisol are:

1. Hardest and slowest flood/fill you can get without causing smearing under the stencil and/or stressing out the mesh. 

2. Lightest and fastest print stroke you can get without chattering that completely clears the mesh.  Most upright angle possible.  Requires very sharp blades, which I'm realizing need to be maintained more around here.

The slow flood helps solve dilatant flow related of issues (or is a plastisol on press technically rheopectic?) and also discourages the opposite, viscosity breakdown, that can occur with some inks on long runs.  Light and fast print lays down more ink than slow and hard and more on top with a better hand/finish.  Also speeds up your production so long as you only flood as slow as you are indexing.   

There's always exceptions and having seams and such up on the platen change the deal often but so far the above has worked well in here.

[alan802]

For special projects or jobs that I want to try a "one hit" whatever color, we will use the fill stroke, but with a twist.  I'm also using Joe's blades for a fill stroke instead of an aluminum flood bar that we are all familiar with.  Pre-loading the mesh will do several things for you that will give you more opacity.  I have seen instances where a fill stroke did very little to influence the print in a positive way but for the most part, white inks play much nicer when using a fill stroke versus a flood.  To those who think it does nothing...do some testing.  Set aside a few hours, a few test screens, and a bunch of test print fabric and get after it.  The fill stroke allows you to print faster, use less pressure and that will in turn lead to greater opacity with less effort.  That's the goal and there is no doubt it works, if done correctly.

I will say that using a fill versus flood doesn't do much if you don't commit fully and do it 100%.  And it's possible that you might not see much change between the flood and fill until you reach a certain point.  What I mean by that is if you preloading the mesh, half-assed, filling it maybe 50-75%, it might look like you're really doing a hard fill but in reality, you're not accomplishing much and your results won't reflect the benefits like filling the stencil 100% will do.  Getting a 100% pre-loaded stencil isn't impossible with an aluminum flood bar but it's much easier using a squeegee blade and that's when we see the best results.  For most of our underbasing we will still use the standard flood bar with hard pressure but when we want to maximize a mesh's ink deposit we will use a squeegee blade.  I will say that if you aren't completely committed to the concept, for example using a hard fill but still using a lot of pressure and a slow print stroke, then you're wasting your time and you might as well use a flood and move on.

Like others have already stated, I've found that mesh with thinner thread and larger openings work better for white ink and this approach.  Theoretically, thicker thread mesh should allow for more ink deposit (up to around the 150 range) therefore more opacity but in the real world it's how that ink transfers through that mesh that overrides the theoretical numbers on a mesh chart.   The ink volume numbers are so close between like mesh counts with different thread diameters that it stands to reason that you should choose the mesh count that will allow you to print with less pressure and faster print stroke.  If you've got 12-15 newton screens with standard mesh counts then you probably won't see AS MUCH improvement over a flood stroke.  I'm not saying don't try but don't get discouraged because it's not the magic potion.  I can't remember the last time we printed white ink through standard thread mesh.  I think it comes down to mesh count and tension, as usual, and the more control you have over those variables the more success you'll have with most any approach you take.  When you have those two variables in control you can do a lot more, and you can also do a lot more wrong and still get decent results.  I don't want to turn this into that type of thread and I do realize that shops all around the world achieve great results with low tension and standard mesh counts, but I know that we've gotten better results across the board when using thinner threads and PROPER tension.   Let's not talk about WHAT can be done with sub-par equipment and tools, let's talk about how much can be done with optimum equipment and control over the variables.