Index separated discharge

[Pangea]

I'll be printing my first index separation with discharge next week and wanted to get an idea on mesh count to use? My feeling is 230 to make sure there's proper ink saturation but 305 to hit all the details. Any help would be appreciated!

[ericheartsu]

I'll be printing my first index separation with discharge next week and wanted to get an idea on mesh count to use? My feeling is 230 to make sure there's proper ink saturation but 305 to hit all the details. Any help would be appreciated!

What DC are you using?

[BP]

What LPI are you planning to run? That will tell you what mesh to use.

[Pangea]

What DC are you using?

CCI

[ericheartsu]

What DC are you using?

CCI

Personally i think 305 will be to high for that CCI. 230 might work ok?

[Sbrem]

What LPI are you planning to run? That will tell you what mesh to use.

Since indexing doesn't use lines per inch, what is your resolution? in pixels per inch? That will determine your grain size, which should help you determine your mesh. For instance, 100 ppi is 100 little square dots per inch, so 200 ppi is 200 littler (?) square dots per inch, half that size... I'm curious too, I haven't done an index sep in years, but usually 180 - 200 ppi.

Steve

[brandon]

We do discharge index with CCI. 225 and 300s will be fine

[Colin]

I would assume very very little dot gain with DC.  Make sure your reg is tight!

[brandon]

I would assume very very little dot gain with DC.  Make sure your reg is tight!

Very true

[Pangea]

I separated at 200 DPI, I'll give the 230s a try. Thanks guys!

[Dottonedan]

I separated at 200 DPI, I'll give the 230s a try. Thanks guys!

A word of caution:


Try to avoid having your resolution so close to your mesh. For example DO NOT use 200 resolution on a 200 mesh. Avoid anything close to that scenario. Go up higher to a 255m 280m, or 300m. If you have none higher, then you will need to accommodate that 200 mesh and drop the rez...for a slightly larger dot (square) such as a 170-180 rez. I think in your case, doing 200 and a 230 mesh... being 30 away either higher or lower, will be a safe.


Reason being, as the rez gets close to the mesh count number, you begin to get strong mesh interference. There is a name for it that is different than Moire, but You will see what looks like moire, (in the stencil) and thus into the print. HORRIBLE when this happens. You get a big ole rainbow looking thing in your print.


170 on 200 mesh
200 on 230 mesh
233 on 305 mesh
266 on 355 mesh


The cool thing about this indexing or stochastic, is that you can utilize various size (resolUtions in your file), to take advantage of gradations and textures etc. (in special effect inks) that are in your sim process.
Say your sim process is at 233 rez but you also have 2 stacked layers of puff ink for a more 3D look...and that puff ink has breakups or fades. Dimples for example. You can do all of this one in one file.

[tonypep]

Mesh interference is what you want to avoid as Dan has mentioned. Depending on climate and shop (and ink systems), some lubricant and penetrant can help and prevent premature drying in the screen. CTS and Triloc (or other pre-reg systems) obviously speeds things up by a lot.

[Pangea]

Wanted to update and thank everyone. I was super nervous to print this but it ended up coming out great!