Onyx/Epson VarDot profile

[SWCL]

I'm starting to create profiles for the Rip (finally) using the knowledge gained from the threads on here & the training workshop I attended.

I've managed to create a profile for our JV3 160s Ultra, using Inktec inks & on DigiSol 5000 5-7yr vinyl.. We were using a profile for some Oce media which gave 'OK' results (compared to the god awful stuff that was coming off using the ancient v.5.6 profile!) - but for reasons unknown, having only changed the capping station.. it started over inking everything I printed?

So I was forced to try profiling & didn't do a bad job, for a newbie - Media ****yzer says Spot Colour accuracy is 75.9% for my profile compared to 57.5% for the Oce media - however we fail to hit colours like Pantone Yellow & Red 032 which is important to us, but thats another story..

I'm trying to create one for the Espon 9600, which at the moment only has Epson profiles on it.. but we use NO epson media! - Canvas is passable with some colour tweaks in RIP but is obviously not ideal.

I'm getting stuck at the first hurdle though.. choosing the Dot size.

I see I can select different dot sizes for C M Y & K - this confuses me somewhat as I cant work out what will happen to the 2 colour combo's (R G B) - can't get my head round it more than anything & am in need of some reasurance I think.

Is there a way of determining which setting is best using the eye one? as during that part of the profiling workflow you can access the eye one measurement tool.. or do you just visually check which dot setting gives you best coverage/least artifacting per channel & do it that way?

The var dot patches I have printed off, the -10 line has great coverage on the RGB, but really weak CMYK. The +2 line is much better for CMYK, but the RGB patches run into each other badly.

Also the media I'm trying to profile (Inktec Matte Photo Paper) has a golden sheen to it, but seems to react to too much ink? When the ink coverage is within limits the golden sheen can be seen over the whole print, but it seems when it is too much the area of heavy ink lays on top of the surface..

I will try to upload a picture so that you have more of an idea of what I'm trying to describe.

Chris.

[eye4clr]

The Variable dot thing is pretty easy. Look at the 1, 2, and 3 of each ink color as a progression in dot size with 1 the smallest and 3 biggest. Start off your restrictions with all set to 100. So C1=100, C2=100, C3=100 and so on for each color. Light inks should all be at ZERO.

Use the EyeOne to determine max chroma (saturation) for each full color ink. Then take the value you find from the test print and consider that a percentage of 300 (100 of each dot size). Remove ink starting from the 3's and then progress into the 2's, then the 1's if needed.

Example... let's say you determine you like 65% cyan from the test chart. 300 x .65 = 195. So C3=0, C2=95, C1=100.

Then set the light inks as a 90% progression from the dark ink's 1 value. IOW, if C1=100, lc3=90, lc2=82, lc1=74.

Hope this helps.

If you're faced with a sliding scale for dot size like in Onyx 6.5, leave it at the default middle position and you'll get great results.

[SWCL]

Thanks for the reply eye4clr, I understood about 99% of what you said

I have seen the C1, C2 etc. described in the manual or one of the profiling guides I have downloaded.. but have never managed to get that to come up in the restrictions.

It may do this time but I've not got to that stage yet. I wondered if the mode I'm trying to do it in is correct?

I'm trying to profile using the media group 'UltraChrome VarDot',
ink configuration 'CMYKcmk VarDot (Photo)',
process 'CMYK',
Mode '1440x720-MD', 'Stochastic'.. does that sound right so far?

I realise (from what I have read) that using VarDot means you can print something at 720-MD that looks similar to something printed at 1440x720 non vardot.. or at least that is what I'm lead to believe.. so profiling at such a high res in this mode may be a bit over kill but I thought I'd start high & work my way down..

Also - a problem I found when doing the JV3 profile was that when I measured the ICC patches, the mesured swatch colour was waaaay off the desired colour on the left! - what would have caused that?

Here's the screen I'm looking at now to determine drop size



Here's the swatch for dot size selection (note on +10 the ink is running off the page in RGB)




here's the over inking?? - 50% Blue, matte effect on top of the sheen


& again in 50% Green & 50 + 60% Blue


-7 CMYK weak.. RGB ok (cmyk looks ok in pics but not in the flesh)



+2 CMYK ok.. RGB pooling / running



Last one to show the sheen / reflectiveness of this 'matte' paper - to the left of 0


Hope all the pics help identify what I was trying to describe in the first place!

Chris.

[eye4clr]

stumped.

I've not used v7/epson combination so far. So I must confess I'm not familiar enough with the screen shot you were kind enough to post.

Personally, i've always used the Dark Ink Restriction test file since it gives the CMYKRGB and the combined CMY ramps all in one print in 2% increments. If i remember the epson mode choices are many. Maybe try looking for the 720MD choice instead of VarDot. It may simplify the process tremendously.

[jcuads]

This step is to determine the ratio of small to large dots within the channels. As the instructions state, choose the dot that provides the smoothest output without artifacts. I don't use the measure tool, Idon't know how one could for this procedure, simply determine by eye. It is important to do this step prior to ink restrictions as it can drastically alter the amount of ink laid down. Some of the ink configurations in Onyx Production House 7.1 have predetermined VarDot settings, as in "CMYK enhanced" for the Mimaki JV3 SPII. The following step is to do Ink restrictions, there I suggest doing the Cyan and Magenta by Chroma the Black by Lightness and the Yellow by density relative to the other channels. Hope this helps

[bigbly]

Don't forget if the light inks are off this will be a little grainy so don't stress to hard over it. I think I just left it at whatever the default was for my epson 4000

[SWCL]

Hi everyone *sigh*

I'm REALLY struggling with this profiling mallarky! - I'm sure it'll put me in an early grave if I can't figure it out soon

Still working with the Epson, I'm trying to create a profile for our 'artists canvas' - as it turns out that just popping in the correction for the pre-loaded media did not work as the prints are WAY to dark.. & 2 1200mm x 840mm wraps have been sent back

So, time to make a profile

Doing it as suggested, as a 720-MD rather than a VarDot profile.

Have an Eye1 Pro, have downloaded PM5 Pro to do the Delta E / Lch / chroma measurements..

Now I'm stuck..

I've measured the Delta C & made a note of the values.. I've gone through the values adding an arrow to indicate whether the the next value down (from 100%) is higher / lower / the same.

Looking at previous posts - which I've had to re-read 15 times to understand - I need to find the point at which the Chroma values stop fluctuating lower/higher, then pick the % which is -1 DE below that.

Now the reason i'm confused..

100% is 58.8 Delta C according to PM5 (or 58.92 using the lch measuring in onyx profiler)

The figures don't stop fluctuating until 32% - as far as I can tell - which gives a value of 56.8 Delta C.. with the -1 DE lower than that being 30%

My concern is that where it stops fluctuating, it is already -2 DE of 100%

Do I choose the 30% as the restriction (regardless of being -3 Delta E below 100%) or have I messed something up?

Its canvas so is textured - but not gloss. Epson 9600, 720-MD Stoch, Inktec Inks.

Light inks were off, all other inks C1, C2, C3 etc. were 100%, transition set to 4 for all inks.

[eye4clr]

If you loose on 3 dE from 100 to 30, holy crap man, go with 35 and sleep well at night knowing you've save a TON of ink.

Remember, canvas is very forgiving as far as dot visibility goes. You just want to make sure you're maxing the gamut (chroma) and not wasting ink.

[SWCL]

I'm still doing something wrong somewhere..

Remeasured the swatch this morning, plumped for 34% C which is now just under 1 DE lower than 100%

CMY ramp was greeny so I've gone for 30% Y just to see if it came out more neutral

K is 1 DE lighter at 96% - so restricting at that

Now M is the problem.. read the swatch there is some minor fluctuations of 0.1 DE etc as you go down the ramp in places but it doesn't stop doing that until 42% but by that time the difference is 7 DE! so I've chosen to ignore the minor fluctuations & gone for 86% which is 1 DE below 100%

That gives me figures of, (percentage of 300)

C = 102
M = 258
Y = 90
K = 288

I popped in those figures (M1 = 100, M2 = 100, M3 = 58 etc.) & reprinted (with light inks still at 0) & supprise supprise, the CMY ramp is now really Magenta.

Yellow is also pretty weak - but reds / greens look ok (to me)

[eye4clr]

the numbers do look pretty far out of balance. The epson inks are quite strong in Y and weak in M, so i'm not surprised at the direction they're taking. I'm mostly suspicious of the super low C.

When you measure the chroma, are you using the DeltaE 2000 calculation? 2 degree observer? and d50? If not, especially the d50, it could skew the balances.

Also, is the canvas glossy? If so, you may be better off doing it by eye. And you may not be able to get good readings for your linearization and subsequent icc. One big clue to the degree of possible success is the smoothness of the linearization curves. If they've got lots of little or large spikes up and down, the light is bouncing around the texture of the canvas and not bouncing correctly back into the instrument.