Print Ready Screen Printing advice...


Hi guys,

I have some questions regarding setting up print ready files for screen printing.
I'm currently in the process of converting 30 illustrations into Illustrator to clean up and print ready.

I've read quite a few articles, but they all seem a little different. I've also checked some screen printing websites but the limit of the advise appears to be 'acceptable file formats' with no guidance as to setup. To note, these will all be on t-shirts.

I'll take a simple design as an example.

Screen Shot 2012-09-06 at 15.12.48.jpgScreen Shot 2012-09-06 at 15.13.05.jpgScreen Shot 2012-09-06 at 15.13.15.jpg

It's not yet cleaned up properly, I'm using it as a test to work out the separations/layers/colour assignment.

So as you can see, I have three layers. The grey is the temporary background layer.
The second layer is the entire outlined shape with a black fill, with the white to be overprinted.

However I've also read that the white would be printed first, meaning that I should effectively have this in reverse?
IE. The white layer larger than required to account for misalignment.
The black layer having the intended white areas cut out, as the black will be printed last.

Is this looking correct from a separations point of view? Should it indeed be reversed?

Also, regarding assigning colours, I have my Pantone swatches out. Should I be using the Solid coated library?
I was thinking of labelling the layer e.g.. unspecified black. If I do this and create a new swatch and just select spot colour (without selecting pantone library), will the printers assign the colour themselves?

An additional but side question is that the client is unsure about t-shirt colours yet, so I want to provide working files where they, or the printers would be able to alter fill colours as necessary depending on the colour. What is the best way to achieve this? Or should I just create separate illustrator files with variation in fill colours? Are printers quite easy going if it comes to a client saying 'hey I'd actually like this on a blue t-shirt. Can you change the blue fill on the x to white?'

Many thanks guys,
Oph x
How much do you know about the screen printing process? Finding out a bit about it might help you improve your designs for the process.

To move the artwork from computer to a t-shirt, the design is printed onto an acetate. that sheet is then layered over a silk coated in an emulsion and subjected to an intense light. The purpose of the acetate is to prevent areas of light hitting the emulsion as where the light hits, the emulsion sets creating an barrier which cant be penetrated by printing ink. Areas of the silk which aren't subjected to light don't set and so printing inks can pass through which is the bit that creates your image. The only two options are light and dark and so the best acetate artwork to block the most light is sold black, anything else (ie greys and colours) negatively affects the quality of the finished print as they don't block out enough light. For that reason you should be designing in black and white and supplying the printer with a written breakdown of the colours to be used.

Printing process...
Traditionally it's easier to print a dark colour onto a light colour than trying to do it the other way round (ie; its easy to put black over white but not so simple to print white onto black). It's also a good practice where possible to have a single surface for all other colours to be printed on. This prevents uneven prints and coloured inks displaying differently as they travel from fabric to print and back again. (does that make sense?)
Looking at your design, the most ink efficient wy of working would be to print the white first as it's the dominant colour and then add the black detail over the top. Doing it the other way would waste a substantial amount of ink.

The best thing you could do would be to give your printer a call and talk through the process with him (maybe even go down and see it all in action) as each printer has their own way of working.
Thanks for your replies, I'm quite familiar with screen printing but only through university. I'd imagine professional workflows will be slightly different.

I've rang around a few places this morning and they're all happy with PDFs with no colour assignment nor bleed edges to account for misregistrations. Interesting.
So this means I just supply a PDF of the artwork to the client and leave it at that. Something seems a little amiss from my side as though I won't be doing enough to print ready as I would with a regular print based job.

I think I'll supply the client with the working files with colours in separate layers anyway, that way if really necessary they can adjust what they need to if it's required.
Being new to freelancing, I think I have a lot of missing practical information that you just don't learn at University.
University is great for creative thinking, but not great when it comes to setting you up for dealing with clients, the business side of things, and dealing with printers of varying types.

I made more of an effort after posting here to really understand the role of printers and how what I do affects them, how to make their life easier too.

The one that was particularly helpful and all ears to helping me understand their process and mine as a designer within that have offered for me to go in for a few days to see what they do, witness the process, and sit with their in house designers while they prepare artwork ready for print.
The gentleman on the phone seemed quite keen, and he said that it would be good as I would see all manners of files coming in ranging from jpegs that need full reworking, customers who have supplied files with no idea of scale nor colours, to artwork supplied by a designer on behalf of a client that would require colour assignments and separations only.

I'm made up that they're willing to help me understand.

Thanks bigdave for prompting me to go and find things out :)