Keeping your details intact!

-

Washing out screens to minimize detail blowout:  


Like everything, there is a multitude of ways a thing can be done, but some are better than others.  Washing out screens after exposure is one of those things.  When exposed to light, the exposed emulsion hardens, where it has been shielded from UV light it remains soft and responsive to being washed out of the screen mesh.  That quality is at the heart of modern screen printing.  The emulsion will also harden progressivly through it's profile, with the emulsion nearest the light source being harder than the emulsion deeper in through the film thickness.




This progressive hardening can be used to the screen printer's advantage in that washing out an image from the "hard" side, into the mesh can be done much more aggressively than from the "soft" side of the emulsion.



The TLDR? Spray out your image from the hard side of the emulsion to retain your detail!  Spraying out from the softer side has a higher risk of of losing detail.

Comments

Post a Comment

Popular posts from this blog

Advanced / CMYK Process Halftone Printing

-
Image
CMYK Halftone Magic- A majority of screen print work is printed using inks mixed for a specific color.  Qualities such as color and transparency are controlled on a per-batch method. The color in the bucket is what will print on the page. This is "spot color"  Another prevalent color methodology is CMYK process color.  CMYK is printed using Cyan, Magenta, Yellow and Black. (Black is noted as "Key" in CMYK.) The combination of these four colors along with the variable dot size of halftone, can replicate a wide color gamut. Interestingly, if only solid color inks are overprinted CMYK only yields seven colors.  It's the halftone that provides the color range. Rather than being mixed in the bucket, the colors are mixed in your eye!  From color laser printer pages to vehicle wraps, CMYK halftone printing is everywhere! Printmakers can lever CMYK technologies to get full color prints with minimum stock of ink colors.  Nothing comes for free thoug...
Read more

Fixing pinholes in an exposed screen

-
Image
There are times where defects show up in the finished screen.  In some recent screens I've noticed some pinholes in critical areas of the screen.  This probably comes from not enough effort degreasing my screens after reclamation.  While that's good to keep in mind for a future screen, I want to get going with today's printing!  Fortunately, the fix for pinholes is easy.  Use some unexposed emulsion and a paintbrush and paint the pinholes over.  Then put the screen back in the exposure unit (without artwork) and re-expose the screen to harden the painted in areas.  Pre-existing emulsion areas can benefit from post-hardening and the filled in areas will be repaired.  The screen will be ready to print in five minutes or so.  Good for minor repair and better than starting over!
Read more

Technique - Rubylith

-
Image
Rubylith is a little different than what has been discussed to date.  It resembles the hand cut stencil in that it is a hand cut process but unlike the hand cut stencil the final step is to shine high-intensity light through the Rubylith to a photosensitive emulsion.  The Rubylith prevents the emulsion from chemically setting. This is another "positive" process.  Where the Rubylith has masked the emulsion is where the ink will go on the print. Rubylith is not sensitive to light and is made of a two layer plastic film.  The top layer is red and the carrier is clear to light pink.  The objective with Rubylith is to use an x-acto knife to cut the artwork out of the red layer while leaving the carrier layer underneath undamaged.  Small cut-throughs are not a problem but if you've made ribbons out of it, lighten up on the blade or move back to a regular stencil. Cutting takes a bit of practice, my first Rubylith cut almost fell apart!  Rubylith can h...
Read more