Photoshop Advanced Induction

DIGITAL PREPARATION OF POSITIVES FOR SCREEN PRINTING

• started of with a desaturated layer (layer 1)

• Threshold adjustment (pixels can only be black and white)
• Clipping Mask (Release clipping mask) isolating a layer so any changes only affects that layer.
• *OVERPRINTING - getting a new colour from to colours
• Maximum frequency for screen printing is 50 ppi.
• Angle (Moire Patterns) for one ink is 15 degrees

WORKING WITH HALLF-TONES

• Turn image to grayscale and save as a tif.
• Don't output from Photoshop but output from Illustrator. *USE BLACK AND WHITE PRINTERS
• *Workshop file = Illustration PDF.

BITMAP ON PHOTOSHOP

• Increase resolution because we are working with a bigger page (1,200)

• Frequency no less than 50 (540) and angle of 15 degrees.

• *Workshop file = Photoshop Bitmap technique.

ALTERNATIVE TECHNIQUES

Digital Colour Mode (CMYK = process colour (for ink/printing) and RGB(screen)) 

• Shade of grey in the channel is directly linked to the amount of ink in the channel
• CMYK can be considered as information about ink or printing an image
• Frequency - 50plimax
• 4colour angle - 45. 75, 15...
• Photoshop - split channels create greyscale of each ayer and bitmap each image applying the halftone (using different angle for each positive).

• SPOT COLOURS - one spot ink us used to print a specific colour
• CMYK - four process
• PANTONE COLOURS - spot colour references in commercial use - commonly use for branding for accurate colour options; insuring consistency. 
• Pantone colours have a unique reference colour and is a direct reference for the printer to choose the right reference colour
• Each swatch on a pantone colour indicates the base colour mixture for that pantone colour.

EXPLORING SPOT COLOURS ON PHOTOSHOP

• CHANGE IMAGE TO GRAYSCALE BUT NOT REALLY NECESSARY
• NEW CHANNEL --> COLOR LIBRARY -->  BOOK: PANTONE Solid uncoated
• SOLIDITY PERCENTAGE - indicates the opaqueness of the ink/colour
• SPOT COLOUR CHANNELS file formats - TICK 'SPOT COLOURS' under save and you can save it as a Photoshop or a TIFF file. 
• Go to Illustrator to print spot colour
• *ONYL USE HALFTONES (angles) IF TINTS ARE USED.