In the Metric System, the mass per unit area of all types of paper and paperboard is expressed in terms of grams per square meter (g/m2). This quantity is commonly called the Grammage, though printers in most English-speaking countries still refer to the "weight" of paper.

Offset printing uses plates made of aluminum, These plates used to transfer an image on a rubber "blanket", and then rolling that image onto a sheet of paper. In Offset printing the ink is not transferred directly onto the paper. It is the best choice for larger quantites, and provides accurate color reproduction, and crisp, clean professional looking printing.
No plates required for Digital printing,It is like a good quality colored photo copy which uses options such as toner (like in laser printers) or larger printers that do use liquid ink. Digital printing mainly used for lesser quantity prints. The benefit of digital printing is it’s variable data capability. When each piece needs a unique code, name or address, digital is the only way to go. Offset printing cannot accommodate this need.

CMYK refers to the 4 primary colours that are used in a printer to produce colours across the full spectrum.
C - Cyan
M - Magenta
Y - Yellow
K - Black
By mixing these four colours in varying amounts, a high quality printer can accurately reproduce almost any colour except Silver and golden.

Lighter weight papers say "value" and are economical for mailing, while thicker papers typically are more opaque and more durable, making them a good choice for pieces that feature a lot of text or are intended to have a long shelf-life.

Lighter weight papers say "value" and are economical for mailing, while thicker papers typically are more opaque and more durable, making them a good choice for pieces that feature a lot of text or are intended to have a long shelf-life.

Being a totally different process to varnishing and coating, this can be described as a ‘plastic sheath’ which is applied involving a heat process. Lamination is designed for card stocks (i.e. 200g and above) and cannot be applied to paper, ie. 150g. It is a more expensive option but the gloss option particularly, is very durable and prevents cracking when creasing and folding on card.
GLOSS LAMINATION is very popular on brochure or report covers, offering a very high gloss durable finish.
MATT LAMINATION is used extensively on brochure or report covers, creating a ‘plasticy’ matt finish. The down side is that it can be prone to finger-marking and scratching. A popular use is to matt laminate and ‘spot’ UV varnish to create a matt and gloss contrast.

Resolution should be of 300 dpi.
Pictures and graphics pulled from the internet are often low resolution, typically 72 dpi or 96 dpi. Avoid these graphics, as they will appear pixilated and blocky when printed.
Also note that you should save all photos in CMYK mode, not RGB mode when possible. Images saved in RGB mode may not print properly. If you are unable to save your image in CYMK mode.