Film "ghost" on the screen + LexJet Instant Dry Clear Polyester

[NeroInferno]

Originally Posted by Iron Canvas Studios

dried in the oven?!

Top exposure frame:


Bottom oven (i believe you call it drier):


Thanks
Fabio

[Andymac]

It's all ok.

that shading of the clear material is where the light was slighly blocked, compared to clear glass. Some materials make it worse than others (frosted mylar, drawing tissue)

When the light is blocked, because it was not exposed all the way through, it loses a little more of the surface of the stencil during washout. It's actually a bit thinner.

this is ok as long as there are not serious pinholes. if you expose longer, it will cure through better.

your coat looks a little thick, press harder to get the emulsion coating a bit thinner, I bet the ghost of the square on the paper doesn't show as much.

The idea of printing the film flopped on the other side, and film emulsion being against the glass and not agianst the emulsion of the mesh, is wrong. If you try to do halftones and fine lines, they will close in due to the thickness of the film and the light bending behind the black of the positive before it reaches the emulsion.


Fabio show us a print. that is a nice exposing unit....but... you have a stencil, the first of thousands - it didn't fall off the screen, now print it! Your stencils will only get better, don't worry.

Print!

[squeegeethree]

Print time.

I still think it's your emulsion being sticky/wet. Often when you have thick uneven coats, such as you're pictured, force drying with fans or heat just dries the outside "shell" of the emulsion on the screen leaving the inside damp. When this happens it takes even longer for your screens to dry.

Anyway it doesn't look like it's affected anything. Next time you come to New York I can show you how to coat a screen.

[NeroInferno]

Originally Posted by Andymac

this is ok as long as there are not serious pinholes. if you expose longer, it will cure through better.

your coat looks a little thick, press harder to get the emulsion coating a bit thinner, I bet the ghost of the square on the paper doesn't show as much.

Okay, thanks for the tips Andy!

I was thinking a thing I though during the coating of the screens. I opened the emulsion can (1kg) and coated simply 8 screens, 2 on the bottom 1 on the top. Alle the screens were 23x31" OD. Now the emulsion can is pratically at 1/4..can this confirm I use too much emulsion for every screen!?

Fabio show us a print. that is a nice exposing unit....but... you have a stencil, the first of thousands - it didn't fall off the screen, now print it! Your stencils will only get better, don't worry.

Print!

I'll print something at the end of next week..I'm leaving Rome for a little journey of 4 days..monday evenining I'll go to buy some others inks from another manufacter and test them soon.

Originally Posted by squeegeethree

I still think it's your emulsion being sticky/wet. Often when you have thick uneven coats, such as you're pictured, force drying with fans or heat just dries the outside "shell" of the emulsion on the screen leaving the inside damp. When this happens it takes even longer for your screens to dry.

Okay squeegee, I'll check after exposed the screens from the same batch, that are still inside the drier.

Anyway it doesn't look like it's affected anything. Next time you come to New York I can show you how to coat a screen.

I hope to be able to coat a screen before I'll have the money to come to visit your studio in New York

Do you think raising the drying temperature for the screens will help me or will affect the exposure? Now is setted to 40°C but i'd like to raise to 50°C or 60°C

Thank you all guys,
Fabio

ps. i'm leaving now good weekend to you all

[bongalong]

man, youv'e got some nice equipment!

if the coated screens were dry, i think the "ghost" image is coming from your films not being dry enough.

you can dry the screens at room temperature, i've been doing this for years without any problems, just coat them the night before to be sure.

the amount of emulsion you have got on your screen depends on what mess it is and how many pulls you do. a course mesh will hold more emulsion than a fine mesh. therefor i would recomend just doing 1 pull on each side on your courser screens. 2/1 on your finer screens. print side first then the squeege side.

dry your screens facing down, you want the stencil to be thicker on the print side.

like others have said, every pull of the squeege makes you a better printer. once on the press you'll realise what you have done wrong or how you can do things better next time around.

cheers.
oli.

[Andymac]

Lex, I have to disagree.......that shading happens all the time when the film you use blocks light. Even clear film in a few layers will make that. Ever stuck 2-3 pieces of tape on a posi? remember the mark it makes on a stencil after washout - it's thinner, right?

that's what's happening here. In combination with a thick coated screen. (that's a particularily ugly example in your first pic Fabio - congratulations!)

it has nothing to do with being dry or not.

40 is almost too high (over 100 degrees F) stencil gets damaged above 100 or something near that (see individual spec sheets)

I've forgot and left my heater on (humidity here is 80-90 sometimes, i have to dry my screens with heat to drive the moisture out and get good water resisitance) and had the temp over 100, the screens still worked, but at some point it won't. 40 should be your max Fabio.

Places where the humidity is low (below 50% RH) the screens will dry and cure complelely through, where it is high they may only dry on the surface. OK for solvent based inks, sometimes bad news for Waterbased on long runs.

but whatever works, eh?

[squeegeethree]

Andy I'm using the same film and ink set and I never have this problem.
Of course you should be able to sort of see your image on the screen and perhaps where the edge of the film ends but your emulsion shouldn't be stained black from the positive. It should be a slightly lighter version of the color of your emulsion.

The lexjet film is instant dry. It's 90% dry the second the printer stops printing and 100% dry 5 seconds after that.

[squeegeethree]

Actually I wonder if Fabio is using pigment or dye on his films. I guess we won't find out until he gets back to work.

[Andymac]

not stained black. that's just his lighting in those first photos.

to get rid of that, up the exposure to get a more complete cure all the way through the emulsion under the clear parts of the film.

I think he should make a thinner coat first before he fucks with the exposure time - it's GOOD ENOUGH, start printing.

[Andymac]

Lex Luther ... Lexjet ....coincidence? i think not.