2. analog and digital priniting
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The document compares analog and digital printing methods for textiles. Analog printing uses physical screens, blocks or rollers to transfer a design, while digital printing converts electronic design files into dots or pixels without screens. Digital printing offers advantages like variable data, minimal setup, and easier editing and archiving. However, analog printing can produce larger volumes at lower costs for longer runs. The technologies can be combined to leverage their strengths for different applications.
2. analog and digital priniting
- 1. ANALOG AND DIGITAL PRINITING COMPARISON R.B.CHAVAN DEPT. OF OF TEXTILE TECHNOLOGY INDIAN INSTITUTE OF TECHNOLOGY HAUZ-KHAS, NEW DELHI 110016
- 2. ANALOG PRINTING CONSIST OF REPRODUCTION OF IMAGES FROM MASTER IMAGE All conventional methods of textile printing are Analog printing FLAT AND ROTARY SCREEN PRINTING, BLOCK PRINTING, ROLLER PRINTING Master image in the form of flat screen or rotary screen Block Design Roller
- 3. MASTER IMAGE MASTER DESIGN Single colour Multi colour
- 4. COLOUR SEPARATION Manual, Through computer with the help of suitable software
- 6. Screen coating with photo emulsion
- 7. Photo emulsion coated screen
- 8. Exposure to light Washing
- 9. Master image on screen
- 10. Printing operations Screen washing
- 11. MASTER IMAGE ON BLOCK
- 12. DIGITAL PRINTING Design in the form of electronic file on computer Computer is linked to printing machine (Ink jet printer) Conversion of electronic design data in the form of analog image with the help of dots or pixels. No need of design screens, block or design rollers. Also known as printing without screens or plate less printing
- 13. STEPS Master design Scanning Transfer of design data to ink jet printer with the help of software Printing onto surface (Non contact printing)
- 15. ADVANTAGES OF ANALOG PRINTING Analog print technologies print many multiple copies quickly and inexpensively. Analog printing usually does not require expensive coated substrate to print satisfactory images as most digital printing does. Its inks do not require the high degree of refinement and small particle pigment sizes which most of digital printing’s do. Most analog inks cost less than most digital ink. Analog screen printing provides a wide range of single pass ink deposition thicknesses through control of Mesh opening and print paste viscosity.
- 16. ADVANTAGES OF ANALOG PRINTING Screen printing can print opaque inks which cover dark substrate surfaces. Printers maintain their own color “kitchens” from which they can match virtually any color.
- 17. DISADVANTAGES OF ANALOG PRINTING Analog printing permits only very limited variable data printing, Analog methods require prepress set up and preparation Generally, these types of printing are not cost effective for very short run printing and sampling. Analog printing can generate significant waste ink, chemical exposure and harmful environmental impact.
- 18. DISADVANTAGES OF ANALOG PRINTING These printing methods use costly film for screen or plate exposure. The archiving of films, plates and screens demand considerable cataloguing, storage space and furniture.In addition, these films deteriorate with age. Images are limited to the size of the plate or screen image area. Larger prints require that one repeat the pattern and that the design permits seamless connection of repeated patterns.
- 19. ADVANTAGES OF DIGITAL PRINTING Digital printing requires minimal press setup and has multicolor registration built-in to its system. This eliminates many of the time consuming processes and permits quick response and just-in time print delivery. Digital processes can vary every print “on-the-fly” i.e. while production printing, providing variable data, personalization, and customization Most digital printing technologies are non-contact printing which permits printing of substrates without touching or disturbing them. This eliminates image distortion encountered in some analog processes such as screen printing. It also does not require as aggressive substrate hold down methods which can distort or damage some substrates such silk or knitted fabrics.
- 20. ADVANTAGES OF DIGITAL PRINTING Digital technologies can print proofing, sample and short run more cost effectively than analog methods. Digital printing does not use film masters, stencils, screens or plates. It requires much less space for archiving text and images than analog printing methods require. One can readily convert analog images and text to digital with scanning and optical character reading (OCR) software.
- 21. ADVANTAGES OF DIGITAL PRINTING Digital files are easy to transport and communicate. One can send a digital file to any digital printer on the planet within seconds. This permits distribution of design to many locations for quick response printing. Generally, digital printing uses less hazardous chemicals, produces less waste and results in less negative environmental impact than analog technologies. Digital printing is employing sophisticated color matching and calibration technology to produce accurate color matching. Digital files are easier and quicker to edit and modify than analog photographic images.
- 22. DISADVANTAGES OF DIGITAL PRINTING Most digital technologies have slower throughput as compared with comparable analog printing. Digital printing will often cost more per copy than analog printing for longer print runs. It often requires specially prepared and coated substrates. Most digital printing technologies deposit very thin ink or toner layers. This necessitate layering for applications requiring thicker deposits, resulting in slower operation. Digital inks and toners are limited in number and carry high price tags.
- 23. DISADVANTAGES OF DIGITAL PRINTING Most digital devices are printing transparent chemistry which limits their use for white or light shade dyed substrates. This is new technology which requires investment for equipment, and training for skill development.
- 24. WEDDING OF ANALOG AND DIGITAL PRINTING To take advantages of the strengths of both the techniques . Digitally print personalized names or places Screen print repetitive images on garments Analog printing for large scale production Digital printing adaptation for sampling and small production runs.
- 25. COMPARISON OF ANALOG AND DIGITAL PRINTING Special inks in small containers (usually 1 litre capacity) provided by machine suppliers Aqueous pastes are mixed up on site in large batches (Spot colours) 1-5 m/min. Speed 30-80 m/min DIGITAL PRINTING Digital printing bypasses the use of screens. Elimination of screens provides advantage in sampling and small runs at economical cost. The master design in the form of photograph or any design can be scanned and printed onto textiles. ANALOG PRINITNG Analog print uses master image in the form of screens, blocks, design rollers etc.
- 26. COMPARISON OF ANALOG AND DIGITAL PRINTING No difference between sample and bulk. Sample may be different than bulk Instant design registration Need time and skill for design registration Half-tones no problem Half tones not easy Non contact printing Contact printing No screens, No colour kitchen Screen costs, engraving, washing, storage Fully integrated with CAD Analog design information DPI 200 upto 1440 DPI 125, 225 max. Pre and post treatment necessary post treatment necessary
- 27. COMPARISON OF ANALOG AND DIGITAL PRINTING Process colours. Some limitations in colour gamut particularly CMYK four colour. Difficulty to produce bright reds, greens nd blues and many other colours desired by textile industry. Improvement in colour gamut by Hexachrome system: 6 colours includes orange and green in addition to CMYK, outside: Hexachrome Inside: CMYK Spot colours. Unlimited colour gamut
- 28. Paper printing VS fabric printing Require extended process colours CMYK process colours adequate Require more ink. Require less ink to produce particular depth of shade More absorbent. Textured surface. This difference has implications in speed, drop size, drop frequency, nozzle life. Less absorbent, plain, smooth surface Fabric Paper
- 29. Paper printing VS fabric printing Different inks for different fibres Limited ink types Stringent fastness property requirements Low fastness property requirements High DPI Low DPI for design resolution Fabric Paper