What To Consider When Choosing Paper: Paper Facts
NOTE: There are four important aspects of paper to consider when choosing a paper type:
- Paper Weight
- Paper Size
- Paper Type
- Paper Quality
Paper weight is measured in pounds (lbs) or in grams per square meter (gsm). The weight in lbs is determined by weight of a stack of 500 sheets of 17"x22" paper. In grams/square meter, the weight of the paper is, as implied by the name, the weight of the paper measured in grams of a square meter of paper.
Typically, the basic "Plain" printing paper (such as Xerox Vitality Multipurpose Paper) is 20 lb/75 gsm paper. This paper is branded as multipurpose as it is a good weight for Digital Copiers and Printers, including Laser and Inkjet Printers, and is ideal for everyday use in Office environments. Another commonly used paper weight is 24 lb/90 gsm (such as Xerox Bold Digital Printing Paper), which is smoother and slightly thicker, giving enhanced print quality and resolution, lower opacity meaning less see-through, and a more substantial feel and professional appearance.
There are also heavier weights of paper, such as Bond (28 lb/105 gsm or 32 lb/120 gsm), Lightweight Cardstock (60 lb/163 gsm), Cardstock (80 lb/216 gsm), Heavy Cardstock (100 lb/270 gsm), which are used for different applications, such as printed covers for booklets.
It should be noted that when properly loading the paper and configuring the machine, heavier paper weights require the correct setting to ensure proper function of the printer. Failure to correctly configure the correct settings can lead to the following issues:
- Internals adjust pressure and speed for thicker paper - As the internals inside the printer electronically set charge, heat and pressure depending on the paper weight setting programmed, an incorrect weight setting can cause issues with friction applied and print speed of the paper as it passes through the printer. This can cause paper to skew, slip, misfeed, jam, image quality issues or cause rapid wear to internal mechanics such as rollers.
- Heavier paper fuses at a higher temperature - A heavier paper weight means the paper has more mass. A paper type with more mass means that it requires more heat for the paper to heat up in the fusing process for the Toner to properly bond with the paper. An incorrect weight setting can lead to issues with improperly fused Toner, such as smearing or rubbing off.
- Toner applied differently to different paper weights - Differences in paper weights require the Toner be deposited using different charges when applying Toner to the paper. Incorrect tray settings can cause image quality issues such as or mottled prints, deletions, poor print resolution or light or dark output.
Printer paper is cut from their original rolls at the factory into common or custom sizes depending on use. Some of the common paper sizes in North America are:
- 8.5 x 11" US Letter Size
- 8.5 x 14" US Legal Size
- 11 x 17" US Tabloid Size
- 17"x11" US Ledger Size
- 5.5 x 8.5" US Statement Size
In Europe, printers use a different standardization for paper sizes, such as the A standard. Some of the common paper sizes in the A standard are:
- A0 - 84.1 x 118.9cm (33.11 x 46.81")
- A1 - 59.4 x 84.1cm (23.39 x 33.11")
- A2 - 42.0 x 59.4cm (16.53 x 23.39")
- A3 - 29.7 x 42.0cm (11.69 x 16.53")
- A4 - 21.0 x 29.7cm (8.27 x 11.69")
As a result, A4 and US Letter size, as well as A3 and US Tabloid, are similar in size but are not the same.
An incorrectly configured paper tray can result in the following issues:
- The printer may incorrectly detect the paper size when set to automatically select and the tray guides are set incorrectly - To ensure proper function of the printer, the printer must be configured for the correct media size loaded into the printer. While it is unlikely that the North American and European paper systems will be confused for the other, if the tray guides are set incorrectly, or if attempting to trick the printer into printing on an incorrect media size, the tray size may detect as one size system or the other (ie: paper size automatically detected as A4 loaded instead of Letter size).
- The application or the print driver may specify a specific paper size - An application (such as Microsoft Word) or the print driver may specify a specific paper size to be printed on. If the specified paper size is not loaded into the printer, the job may be held for resources or generate a fault code.
- Internals are set electronically for the loaded paper size - Tray guides that are not flush with the loaded media can result in paper misfeeds, print skew or paper jams.
There are a multitude of paper types that exist that go beyond paper weight and size. These include the printing system the paper is designed for, grain direction, paper color, the smoothness of the paper and any coatings on the medium. There are also a number of additional media types such as envelopes, labels, transparencies and more that are not covered in detail here.
- Paper designed for Inkjet or Laser Printers - On Xerox Multifunction Printers and Copiers, always use paper designed for Laser Printers. Paper designed for Inkjet Printers is designed to absorb ink sprayed onto paper without bleeding and evaporate it quickly for fast drying times. Paper designed for Laser Printers are designed to allow Toner to cling statically to paper before being fused to paper at high heat in a matter of seconds and at high speeds. As such, Inkjet Paper is more porous and absorbent than laser paper. Inkjet Paper also contains chemicals to accelerate ink drying times that may affect the manner in which Toner is bonded to the paper, resulting in poor image quality, poor fusing and Toner rub off. Inkjet paper coatings may also melt and damage parts of the printer.
- Grain direction, Grain Long versus Grain Short – When paper is manufactured, the fibers within the paper organize themselves in a specific grain direction, similar to wood grain in a wooden countertop. Print grain direction is determined by which direction the fibers run within the paper, if the fibers run parallel with the long edge (Grain Long) or short edge (Grain Short) of the sheet. As paper stocks will often not be labelled with the words “Grain Long" or "Grain" on the packaging, the grain direction can be determined by the direction of the second number listed in the paper size, and may also be underlined (ie: paper size may be listed as 8.5 x 11 for Grain Long, or listed as 17 x 11 for Grain Short). As bending paper against the grain offers more resistance than bending with the grain, it is important to print with the grain parallel to the process direction to avoid misfeeds and jams. It is less of an issue when printing jobs on plain 24lb/75gsm paper but becomes critical when printing on paper weights of 32 lb/120 gsm or heavier that do not bend around the rollers as easily. Also, for folding paper, such as for booklets, brochures and more, the folds will have much smoother creases if folded with the grain direction instead of against.
- Paper Smoothness The smoothness of paper is normally measured on the Sheffield Scale, with the lower the number meaning the smoother the paper is. Typical 20 lb/75 gsm paper (such as Xerox Vitality Multipurpose Paper) measures at around 150; however, more premium uncoated stocks measure in at around 45-60 Sheffield, and coated paper stocks can measure in as low as the 10-30 range. At the other end of the scale, rougher cardstock paper such as those used for covers can reach as high as 300 and beyond. Typically rougher paper jams less frequently than smoother stocks, but smoother stocks often offer higher print resolution and image quality.
- Coated and Uncoated Paper - Paper comes in uncoated (normal) paper and in varying coated paper varieties. When paper is manufactured, it is naturally uncoated and may have a rougher texture due to naturally occurring microscopic pits and valleys in the medium. Some uncoated paper stocks are flattened out further to make a smoother print surface, but to smooth the surface of the paper even further, the paper is coated with a material to fill in the pits and valleys. These coatings may also further vary in that they may have a Satin finish or a Glossy finish. Tray settings that are set incorrectly for the coating on the paper can lead to misfeeds, paper jams, mottle, poorly fused Toner or Toner rub off.
- Use caution when printing on Coated Stock, Photo Paper or Transparencies – Only use paper designed for Laser Printers. Using paper that is not designed for the printing process selected can lead to print quality issues such as poor resolution and possibly jams; however, in the case of Glossy Paper, Transparencies or Labels, media designed for the Inkjet process or offset printing may use plastics or other chemicals that have a lower melting point and can melt during the print process and damage the internal mechanics of the Xerox printer. For best paper performance, use only paper found on the Xerox Recommended Media List for the Device.
- Colored Paper – Paper can also come in a multitude of colors, such as pink, blue, or pastels, depending on the required job. Printing on a colored background will affect image quality as it will offset color prints, and in some cases make text difficult to read. Ensuring the paper color setting is set correctly will ensure the printer prints jobs from the correct paper tray.
Paper is made from cellulose fibers. Most of these fibers are sourced from trees, though some fibers are sourced from cotton or recycled rags. Using fibers sourced from hardwood or softwood trees can also have different effects on the quality and purpose of paper produced. As a result, the blend of fibers used, the quality of the ingredients and consistency of the blend directly affect the quality of paper produced. A paper manufacturer with poor or inconsistent quality control may have poorer results when compared to papers found on the Xerox Recommended Media List for the printer.
- Inconsistent or Incorrect Paper Weight - As the internals of the printer are electronically set depending upon the paper weight specified, Paper that is outside of the stated specifications can cause issues with friction applied to the paper as it passes through the printer. This can cause paper to skew, jam, or cause rapid wear to internal mechanics such as rollers.
- Surface of the Paper is Rougher or Smoother than stated - Rougher paper can lead to poorer image transfer to the paper, such as reduced print resolution. Smoother paper may have image quality issues if the Toner is unable to cling or fuse properly to the medium, or may cling to statically charged components such as the drum, causing paper jams.
- Stiffness of the Paper - If the Paper is too stiff or too flimsy, it may have issues circulating around the rollers or print engine (such as the drums or fuser) inside of the printer, leading to paper jams, especially at high speeds.
- Electrostatic Properties of the Paper - Paper formulas that do not contain the right blend of fibers and chemicals may respond differently to electrostatic charges applied to the paper during the printing process. Paper that lacks the correct electrical properties may have issues with Toner clinging to the paper and cause print density issues such as light prints, deletions and other print quality defects.
- Paper Dust - Poorly made paper may contain lots of finings or paper dust that can accumulate over time in the paper path, leading to clogged pathways and gummed up rollers, leading to tray misfeeds, skewed prints and paper jams.
- Surface Quality is Uneven - Paper with poor density/thickness control can lead to poor image transfer to some areas of the paper, leading to image deletions.
- Poor Paper Formula/Incorrect Paper for Application - Poorly made paper or the incorrect paper for the printer (such as Inkjet paper) can lead to reduced component life, such as the drum, transfer belt, bias transfer rollers or fuser.
- Incorrectly Sized or Cut Media - Modern printing devices are fairly specific when it comes to paper size, poorly cut media that is too large, too small or cut unevenly within even a few millimeters can lead to paper jams, skewed prints or issues configuring the initial tray settings.
- Moisture levels within Media not well controlled during Production – Poor quality control when manufacturing paper can result in paper containing too much or too little moisture, which may result in warped or curly paper, leading to tray misfeeds, jams, poor fusing or Toner rub off.
There are multiple aspects of getting the best performance from a Xerox Device, such as:
- Print speed
- Print quality
Print speeds of a Xerox printer are measured in Pages Per Minute (ppm) using an industry standard print test page and printed single-sided on 16-28 lb/60-105 gsm 8.5 x 11" LEF (Long Edge Feed) paper. Heavier and/or larger paper stocks, paper orientation, duplex (double-sided) printing as well as increased document complexity, will increase printing time and slow print speeds down.
Also, print resolution of a Xerox printer is measured using Dots Per Inch (dpi), with modern printers ranging between 1200 x 600 dpi up to 2400 x 1200 dpi. However, as the dots are small, the surface quality of the selected media is an important factor in the image quality output of the machine. Plain 20 lb/75 gsm paper, or uncoated cardstocks with rougher surfaces such as cover material, may have a surface that is unable to resolve the printers output resolution as well as smoother paper stocks can.
- Heavier paper is more resistant to bending around the paper path - As heavier media is thicker, it offers more resistance when being fed through the paper path of the printer. To adjust for this, the printer adjusts friction and feeds the paper slower to allow the paper to properly pass through the paper path without jamming. Tray settings that have the paper weight set too heavy incorrectly will take longer to print, and may also increase the instance of skewed prints, paper jams and misfeeds. Tray settings that are set too light will increase the likelihood of misfeeds, jams and possible damage to the printer.
- Print with the grain - Printing with the grain is less of an issue with normal bond paper weights (16-28 lb/60-105 gsm), but is still important and critical with paper weights of 120 gsm or more. When paper is pulled into the printer to be printed on, it is bent and curled around rollers inside the machine as part of the printing process. Paper bent perpendicular to the grain structure of the paper offers more resistance than paper bent parallel to the grain. As a result, printing against the grain of the paper can increase the occurrence of misfeeds and paper jams. For best results, load the grain edge of the paper parallel with the printing process.
- Lighter paper weights use less heat to fuse - As heavier paper is thicker, it contains more mass, requiring a higher fuser temperature to properly bond the Toner to the media. Tray settings that are set incorrectly can result in poorly fused Toner, Toner rub off, as well as misfeeds and jams.
- 8.5 x 11 paper with the grains running the 11" side, load in Long Edge Feed Orientation.
- 17 x 11 paper with the grains running the 11" side, load in Short Edge Feed Orientation.
- Load US Letter/A4 Paper in Long Edge Feed for Fastest Performance - On larger printers, as the paper path can accommodate feeding the long edge through the machine first, it can pass the paper through the print engine faster than if printing Short Edge first. For fastest performance when performance is important, print US Letter/A4 Paper sizes in Long Edge Feed orientation whenever possible.
- Simplex Prints Faster than Duplex on heavier settings – Print speeds for Simplex (single sided) and Duplex (double sided) are generally rated as the same print speeds, with the exception that each side of a Duplexed sheet is counted as 1 sheet (ie: 50 pages per minute equals 25 sheets). However, as the paper in a duplexed print job needs to be bent around rollers and fed around the duplex path to print the second side, print speeds are reduced for heavier media. Incorrect tray settings can result in slower duplex print speeds, or increased occurrence of jams in the paper path.
Print Quality Considerations:
- Smoother paper for better Image Quality - A smoother surface on the paper means a flatter area for Toner particles to bond to when deposited on the paper. A flatter, smoother print surface means the printer can print cleaner, sharper text, cleaner solid areas and more accurate halftones. For best results when printing to Plain paper, use a 24 lb/90 gsm paper such as Xerox Bold Digital Printing Paper.
- Rougher paper has poorer Image Quality - Paper with rougher surfaces offer an uneven surface for Toner to bond to, resulting in poorer output resolution, muddier text, mottled solid areas and poorer looking halftones. Also, Toner will not properly bond to extremely rough surfaces, such as textured paper, and may result in light or faded output, deletions, lines, poorly fused output and Toner rub off. Some issues with light output can be alleviated by using a higher density setting using the Lighter/Darken setting.
- Best Image Quality with Coated Stocks Coated stocks use a special coating to fill in and smooth out the microscopic pits and valleys to create an even smoother surface, and comes in glossy or satin varieties and more. The coated surface offers the optimum flat surface for Toner particles to bond to in the pattern deposited, resulting in optimum condition solid areas, halftones and text. Coated paper is the optimum paper choice where image quality is paramount, such as with posters, banners and even flyers. For best results, use media from the Xerox Recommended Media list for the printer (such as Xerox Bold Coated Gloss or Coated Satin Digital Printing Paper).
Paper is highly sensitive to moisture and the humidity levels within which it is stored. When paper is manufactured, most manufacturers produce paper to strict quality standards including a well regulated level of humidity of between 25-50%. The paper is then carefully sealed into packaging that contains a special lining for maintaining the humidity level of the paper for as long as it is properly stored. It is then loaded into cases and onto wooden pallets with an even surface for shipping to the customer. Paper shipped in this condition is perfect for Xerographic applications, but the freshness of the paper is dependent upon its storage conditions when stored, waiting to be used.
As paper is made of wood fibers, it exhibits similar behavior as other paper products such as paper towel. As a result, paper that is improperly handled or stored, can be subject to excess moisture from the atmosphere, which can cause the paper to increase in size, warp, curl or stick together.
Paper with moisture issues can lead to the following issues:
- Damp paper can warp in tray – Paper that has absorbed too much moisture from the atmosphere can begin to become wavy or warp, starting around the edges of the sheet. Warped paper can jam in the paper tray when attempting to feed from the tray, causing a misfeed, and cause wrinkles during the printing process.
- Dry paper can also warp in tray – Paper that has lost too much moisture can contract around the edges of the sheet causing “tight edges”, which can lead to misfeeds, jams, registration issues as well as wrinkles.
- Damp paper can wrinkle in the paper path - Slightly deformed damp paper can lead to paper wrinkling in the paper path. This can result in wrinkled output, paper jams and lines in prints.
- Damp paper can affect Toner bonding to paper - Damp paper can lead to poor Toner application to paper and poor fusing, such as light/faded output, smudging or Toner rubbing off the page.
- Damp paper may Curl - Damp paper may curl more than normal paper would, resulting in curly paper output, or increased instances of misfeeds and paper jams.
- Damp paper may adhere to other sheets - Damp paper may stick to neighboring sheets of paper, becoming difficult to separate and cause misfeeds and jams when multiple sheets of paper are pulled into the printer at once.
Paper Storage Considerations:
- Keep paper in its original packaging until ready for use - Paper is packaged in a wrapper lined with polyethylene plastic that is resistant to moisture and maintains the moisture level of the paper inside the package. Also keep unopened packages of paper stored inside its original cardboard carton whenever possible.
- Carefully handle paper packaging - When transporting or handling cartons or individual reams of paper, be careful to avoid, hitting, denting or dropping packaging as it may deform corners or edges of the paper that are immediately visible. Paper damaged in this manner may increase instances of tray misfeeds and jams.
- Do not store paper on or near the floor - Keep the paper away from environments that experience extreme temperature and humidity shifts and do not store paper flat on the floor as this increases chances of moisture being absorbed into the paper.
- Store paper in a storage cabinet or flat shelf - For paper storage, always keep unused paper in a dry, flat storage cabinet where it can be protected from physical damage and the elements. Always stack the paper evenly on top of the other to avoid curling, bending or damage to the corners of the paper.
- The storage location should be climate controlled - The storage location should also be kept within 68°F/20°C to 76°F/24.4°C and within 35-55% humidity levels for best results. In damp or humid environments, paper, even the paper loaded into the paper trays, can absorb moisture from the air and become too damp to use.
- Paper must be conditioned before use – If the paper cannot be stored in a climate controlled environment or has not been stored this way, the paper must be given a conditioning period before use in accordance to the temperature and humidity levels at which it was stored. For example, a carton of paper stored in a 57.2°F/14°C storage room, brought into a 72.5°F/22.5°C production room must be conditioned for 8 hours before use. The conditioning the time will vary depending upon the temperature difference of the storage area and the number of cartons being used.
- Reseal packages of paper after opening - When opening a new ream of paper and using only a portion of the paper the package contains, reseal the open ream using tape to maintain paper freshness. The packaging contains a special lining that absorbs moisture to help keep remaining paper dry.
- Use only the amount of paper needed in the tray – When loading paper into the printer, load only the amount of paper that the job requires or that will be used in the short term. Paper inserted into the paper trays will absorb moisture from the atmosphere over time, which can lead to the many damp paper issues listed above.
- Store paper in its original package if not being used for an extended period - As paper will absorb moisture from the atmosphere around the printer, if the printer is loaded with too much paper than will be used in the short term, remove the paper from the trays of the printer and back into the original packaging if available.