Tuesday, 25 October 2011

Advanced printing techniques













Yesterday we took part in workshops on advanced printing techniques using our sample silk screens, we covered new techniques including pearl & metallic binders and devore.

So I'll start by explaining some health and safety first before we enter the dye lab, must ensure that dust mask is worn at all times to avoid inhalation of dyes and chemical dust as well as gloves to avoid irritation and staining of the skin. Always mix dyes using a fume cabinet to extract chemical dust from the air.


Pearl & metallic binders 

Recipe
Metallic binders are used at a ratio of 50/50, 1/2 standard binder and 1/2 metallic binder. Mix the metallic binder at a ratio of 5-10% powder to binder. Pigments colours can be added, only a small amount of colour is needed.

Printing method
Once screen printed onto fabric and leave to dry, to fix the pigment use a hot iron on the back of the fabric but keep this moving to avoid burning for approximately 5 minutes alternatively it can be placed in a baking cabinet for 15 minutes at 180 degrees. 









Recipe


Pearl binders can be used on any colour background, pearl binder is used by itself (neat) and is mixed at a ratio of 5-10% powder to binder. Pigment colours can be added and only a small amount of colour is needed. 


The same fixing technique is used for metallic and pearl.




Metallic and pearl print pastes dry very quickly and screens must be washed immediately to avoid blockages of the mesh. 


Devore 

Types of Thickeners and their uses:

Manutex:
Reactive dye printing


Indalca PA3R:
Acid dye printing
Discharge printing
Devoré printing



Devorè Recipe:
  • Measure out 900ml of cold water in to an electric blender
  • Add 180g of Aluminium Sulphate 
  • Blend to dissolve
  • Add 60g of Indalca PA3R powder to water
  • Blend to a thick consistency 1 minute (be careful not to over mix as this will burn out the blender motor)
  • Leave to fully thicken for 30 minutes
  • After 30 minutes rinse thoroughly using cold water first, once running clearly run under hot tap and continue alternating until water is running clear. 


Devorè Printing method:
  • Screen print the paste on to the fabric, making sure it penetrates thoroughly
  • When printing silk-viscose velvet you can achieve a better result if you print on the silk back rather than the viscose pile 
  • Allow the fabric to dry.
  • Use an iron on a medium setting and iron the print until it turns a golden brown colour, be careful not to burn your fabric
  • - Alternatively once completely dry, bake the fabric at 150°C for 15 minutes until the print is a golden brown colour
  • Perform a scratch test in several areas to check that the pile is coming away Wash and finish as normal.


  • Take care when scratch testing not to rub to hard as the fabric will be brittle and may tear
  • Your fabric must be washed if any paste remains it will rot your fabric.




Devore paste can cause skin to burn and is a irritant, make sure gloves are worn when mixing, printing and washing fabric. 



Two Tone Devorè


This is achieved by combining acid and reactive dyes to the recipe. 


The combination we used was Kenanthrol acid dyes and Procion MX dyes in two different colours so when it is rubbed away you can see the contrast, like the example.


Keep in mind that the acid takes to the front of the fabric and reactive sticks to back. So in this example the blue is the reactive and brown is the acid on the velvet devore. 


Example




First mix up acid dye bath:

  • Fill a bucket of cold water, enough to cover fabric 
  • Measure out 1/2 teaspoons of dye, can increase the shade according to the depth of colour shade in 20ml warm water dye bath
  • Add 2 tablespoons of Amonium Sulphate, stir to dissolve
  • Add dye solution to bucket of water, stir to disperse colour 
Now mix up procion dye:
  • Add 1 teaspoon of Procion dye in 20ml warm water dye bath
  • Add 2 tablespoons of Sodium Chloride, stir to dissolve
  • Add dye solution into same bucket of water as acid dye, stir. 

Wet fabric first and immerse fabric into bucket, leave for 20-40 minutes stirring occasionally. Remove fabric and rinse under alternate cold and warm water until running clear. 






Use the same Devore printing technique instructions for two tone Devore.


Two tone Devore on Prada catwalk







Coming soon: Illuminating discharge printing/ pigment discharge printing, flocking and how to fix and finish prints at home using a vegetable steamer and saucepan.