There are a few different models that are commonly used in printed designs. The model used depends on the specific needs and goals of the project. Some key factors that influence the choice of model include target audience, purpose, complexity of design, budget, and type of printing process.
Pixel-Based Design
A pixel-based design model is commonly used for simpler graphics and layouts, especially those intended for online or digital use. In this model, images and elements are created and sized based on pixels.
Pixel dimensions allow for precision and sharpness when displayed on screens. Pixel-based designs are made in image editing software like Photoshop and saved in a web-friendly format like JPG or PNG.
The main advantage of a pixel-based design is the ability to maintain crisp, defined graphics for digital screens. The drawback is that pixel designs do not scale well for print. Enlarging a pixel image often reduces quality and creates a jagged, blurry effect.
Vector-Based Design
For most professional print projects, a vector-based model is used. Vector graphics are created through programs like Illustrator or InDesign. Instead of pixels, vector designs use mathematical formulas and points to draw lines, curves, shapes, and text.
This allows vector images to be resized without any loss of quality. Vector graphics can smoothly scale from something as small as a logo to a large format banner or billboard. This makes them the standard for any high-resolution print application.
Vector designs also separate elements into individual layers, colors, and effects. This helps with editing and adapting the artwork for different formats like business cards, letterhead, brochures, etc.
Raster Image Processor (RIP)
To go from the vector design file to an actual printed piece, the artwork must be processed through a raster image processor or RIP. This converts the vector graphics into a high-resolution raster image with specific dot arrangements and separations for each color.
The RIP slices the design into four standard process colors – cyan, magenta, yellow, and black (CMYK). Each color is assigned a separate plate for the printing press. The RIP optimizes these color separations, dots, resolution, and other factors for the specific press and paper that will be used.
Older imagesetting technology converted designs straight from vector to film for platemaking. But most modern printing relies on a RIP to translate artwork into the raster dots needed for quality reproduction.
Design Applications
There are a number of applications and programs commonly used in the printed design process:
| Program | Description |
|---|---|
| Adobe Illustrator | Industry standard vector design app to create logos, illustrations, layouts |
| Adobe Photoshop | Leading image editing software, primarily pixel-based |
| Adobe InDesign | Powerful page layout program for multi-page documents |
| CorelDRAW | Alternative vector design and illustration software |
These programs allow designers to use both vector and raster techniques in one project. For example, a logo created in Illustrator can be combined with product photos edited in Photoshop for a brochure layout designed in InDesign.
Color Models
When creating artwork for print, the two main color models used are CMYK and Pantone.
CMYK (cyan, magenta, yellow, black) is the process color model used in press printing. The CMYK separations are generated from the vector or raster design files.
Pantone Matching System (PMS) colors are proprietary spot color inks mixed by Pantone for consistent color reproduction. They allow more accurate colors like corporate identity hues. Spot colors are separate plates printed in addition to CMYK.
For the best print results, designers should create and preview artwork in CMYK and PMS swatches. Relying solely on RGB can cause unexpected shifts in hue from design to final print.
Printing Processes
There are several types of printing processes used in commercial printing:
- Offset printing – Most common form of commercial printing using metal plates on a press. Well-suited for high volume orders.
- Digital printing – Prints directly from a digital file without plates. Best for shorter runs and quick turnarounds.
- Flexographic – Uses flexible rubber or photopolymer plates for packaging, labels, newspapers.
- Rotogravure – Intaglio process etching images onto metal cylinders. Ideal for very high volume like magazines, catalogs.
- Screen printing – Ink is pressed through mesh stencil onto substrate. Used for simple designs on t-shirts, posters, etc.
The printing method also impacts the optimal image settings, file setup, and design considerations.
Prepress
Prepress refers to the preparation and processing of the artwork before it goes on press. This includes:
- Color correction and color management
- Image enhancement and touch-ups
- Adding finishing effects like varnishes, foils, or embossing
- Impositioning or arranging pages for the print sheet layout
- Proofing to create a preview print for approval
- Creating film or digital files for platemaking
Prepress helps optimize artwork for the intended printing process and prevent errors before hitting the press. The printer’s prepress team will assess and prep the supplied design files as the final step before printing.
Conclusion
To summarize, most commercial printing utilizes a primarily vector-based design model combined with some raster image elements. The artwork is processed through RIP software then separated into CMYK and any spot colors for the specific presses. Offset lithography is the most common method, but other processes like digital, flexo, and gravure each have their own advantages. Whichever model, method, and tools are chosen, the printer’s prepress team will take the final design files and get them print ready before hitting the actual presses.
