Labels

Labels or pressure-sensitive materials are multi-ply materials that contain various combinations of face sheets (printable stock), adhesives, and removable protective backings (liners). These layers can result in thick materials that are difficult to handle.

Labels are among the most difficult print materials for any printer to feed reliably and print. Factors, such as heat, pressure, and paper path, could make printing on labels quite challenging. For example, temperatures near 225°C (437°F) and pressures to 25 psi can be necessary for the fusing process. Temperatures vary between printers. Check the section for your specific printer. Heavy label stock can absorb heat, which affects toner adhesion and print quality, causing delamination.

Note:  Make sure that you use labels specifically designed for laser printer to prevent labels from peeling off or delaminating.

Label guidelines

Review label designs with a converter or a vendor who has extensive knowledge about labels and laser printers to ensure that you are using the proper type of labels.

For more information about label support for your printer, see Printer-specific paper support .

Label components

Labels are composed of three basic parts: the liner, the adhesive, and the face sheet. Labels may also have topcoats that affect printing. To prevent labels from peeling off, follow the recommended label design guidelines. Peeled off labels could cause jams. The label or adhesive could also melt when the sheet is jammed in the fuser. Choosing appropriate materials for each of these label components helps ensure reliable printing.

Liners

The liner , also known as the carrier or backing, is the material onto which the label is attached. The liner carries the label through the printer and directly affects feed reliability. Liner weights and construction vary based on the printable face stock used. For more information, see Face sheet (printable stock) .

Tissue-backed, plain bond, or bond-like, porous, lay-flat liners are preferred. Liners constructed for use with high-speed laser printers (50 pages per minute or more) may not produce acceptable results.

A liner should bend easily and go back to its original flat state when released. Forms that remain bent may cause paper jams or damage to the edge of the sheet. This bent affects earlier printer models using a corner buckler rather than a pick roller assembly to separate the sheets.

Some liner materials used in pressure-sensitive constructions are called label papers . Label papers are either machine finish (MF) or English finish (EF) papers that are calendered, supercalendered, or coated on one side. An MF has varying degrees of surface smoothness. The number of times the paper passes through the rollers (wet or dry) during manufacturing determines the surface smoothness. An EF is uncoated and low gloss in appearance. Label papers may also be used as the face sheet for pressure-sensitive paper products, such as the materials used in dual web forms construction.

Supercalendering produces high gloss surfaces that may be slick. Some supercalendered liners are difficult for printers to pick and feed reliably. We do not recommend using supercalendered liners designed for high-speed laser printers (50 or more pages per minute).

Some pressure-sensitive constructions use kraft liners or bleached ones. Kraft liners are made from sulfate pulp and are MF or machine glazed (MG). Most MG papers have a high gloss appearance. High gloss, glazed surfaces may increase skew and are more difficult for the printer feed mechanism to handle reliably. Some kraft liners may produce acceptable results; however, we strongly recommend extensive testing of pressure-sensitive constructions using kraft liners.

Tissue-backed or plain bond liners reduce toner contamination inside the printer and improve feed performance. Slick, non-porous liners are harder to feed and increase toner buildup in the fuser and on the backup roll. Rough backings can increase paper path friction, which can cause skew and paper jams. The face material of the liner needs to have a melt temperature that can also withstand the fuser temperatures of nearly 225°C (437°F). A stripped area of a maximum of 3 mm (0.12 in.) can expose the face material to these temperatures and could cause melting or contamination in the fuser.

Excessive paper dust or chaff associated with the liner may affect print quality. If a liner produces excessive paper dust or chaff during conversion, then the debris may be packaged with the material and end up in the printer. These properties as they feed through the printer may also affect print quality. For more information about liners, see your label supplier.

Adhesives

There are three basic types of label adhesives: removable, permanent, and semipermanent (cold temp). All types, with proper design, can be used with your printer. Acrylic-based adhesives are generally preferred for cut-sheet label printers.

The major adhesive-related printing problem is printer and cartridge contamination. The adhesives are semiliquid and may contain volatile components. If the sheet jams in the fuser, the adhesive can melt, contaminating parts of the printer or releasing fumes. To avoid exposing adhesive to the paper path guides, drive rollers, charge roller, photoconductor drum, transfer roller, and detack fingers, use full label sheets.

Zone coating means placing the adhesive only where needed. Paper labels and integrated forms typically use zone coating. In addition, a non-adhesive border of 1 mm (0.04 in.) around the outside edge of the label sheet generates good results. For more information about designing labels for your printer, see your adhesive manufacturer or label supplier.

A stripped edge matrix along the outer border of the stock, combined with adhesive that does not ooze, helps prevent adhesive contamination. This design requires a stiffer backing material to prevent damage when the sheet is aligned on the reference edge. Generally, vinyl and polyester labels are well-suited for this design. Paper and dual web designs may require testing to determine which backing produces good results.

Make sure that the release strength is adequate so labels stay attached to the liner and do not peel off in the printer. Adhesives should withstand pressures up to 25 psi and fuser temperatures of 225°C (437°F) without delaminating, creating hazardous fumes, or oozing around edges of labels, perforations, or die-cuts. Shear strength should be strong enough to prevent adhesive stringers. For more information, contact your label supplier.

Face sheet (printable stock)

Paper, vinyl, and polyester are the most common materials used for printable stock. Printable stock must withstand temperature up to 225°C (437°F) and pressures up to 25 psi. For more information, see your label supplier.

Carefully test the printable stock to make sure that it functions satisfactorily with your printer.

Topcoats

Topcoats for non-paper labels may be either water-based or solvent-based. Avoid topcoats containing chemicals that emit hazardous fumes when heated or exposed to pressure. Topcoats affect the print quality, feed reliability, and adhesion of toner to the face sheet. Topcoats should withstand temperatures up to 225°C (437°F) and pressures up to 25 psi for 100 milliseconds to prevent fuser damage.

Water-based topcoats tend to be more conductive than solvent-based topcoats and are more difficult to fuse. With some water-based topcoats and heavy liners, the fuse grade may fall below acceptable levels. Solvent-based topcoats tend to be lower in conductivity than water-based topcoats. With some solvent-based topcoats, fuse grade is within acceptable levels when heavier liners are used.

Print quality may degrade when using topcoats on labels with heavier liners. Using a lighter liner may reduce the appearance of splatter. Carefully test the labels to make sure the topcoat functions satisfactorily with your printer.

Label characteristics

The materials used to construct labels have a wide range of properties that can affect printing. Volatile components are in the label materials and in the adhesive itself. We recommend that volatile emissions from the label, up to 160°C (320°F), should be a minimal amount. The volatile components, which have low boiling point, produce emissions when heated in the fuser and could emit vapors that can damage the printer.

Preprinted inks can also cause printer contamination, and may be present on one or both sides of the label sheet.

Before purchasing large quantities of labels, make sure that you extensively test the labels with your printer.

Labels with a stripped edge matrix do not have the area around the outer edge of the cut sheet. Labels with a total strip matrix do not have the die-cut stock around and between the labels. This property makes it easy to peel the labels from the backing.

Butt cut labels are cut flush to one another, with no extra area between them. Avoid using butt cut labels without a stripped edge matrix.

Die-cut labels are cut with a non-print area between each label. For best results, do not print within 2.3 mm (0.09 in.) of the edge of the label, of the perforations, or of the die-cuts of the label.

If you are using a butt cut or die-cut label, then make sure that adhesive contamination does not occur. Labels use varying levels and types of adhesive, and various liner materials and face stock papers. Adhesive can ooze from all label stocks. Make sure that die-cuts are free of adhesive stringers. To prevent adhesive contaminations, use zone coating or pattern adhesive with a non-adhesive border of about 1 mm (0.04 in.) or larger.

If zone coating is not used, then we recommend a stripped edge matrix. The stripped edge matrix varies with the type of face stock, liner, and adhesive materials. The following table shows the guidelines for stripped edge matrix.

Note:  Measurements may vary ± 0.5 mm.

Face type

Total weight of label

Edge matrix removal

Location of strip

Paper* (cut sheet or dual web)

140–180 g/m 2

1.6 mm (0.0625 in.)

215.9 mm (8.5 in.) at leading edge

279.4 mm (11 in.) at driver edge (left margin side)

Vinyl

265–300 g/m 2

Polyester and other face materials

Varies


Using cut sheet labels with adhesive applied to the edge of the sheet contaminates and voids your printer and cartridge warranties.

When using pressure-sensitive materials without zone coating, choose butt cut labels without any stringers and with a stripped edge matrix. If a total strip matrix is in the design for the final product, then print before removing the matrix. If the matrix must be removed before printing, then round all corners, making sure that adhesive is not exposed.

Cut sheet paper labels

Generally, cut sheet paper labels work well with your printer.

Coating or sizing to make the paper liquid-resistant decreases toner adhesion and increases the risk of toner contaminating the fuser. At a minimum, paper labels should be equivalent in weight and rigidity to a 20-lb xerographic bond paper.

Dual web forms

Constructing dual web forms involves joining rolls of two different materials (usually pressure-sensitive paper and bond paper) and then converting to a cut sheet product. This construction requires a stripped edge matrix. The liner must be rigid enough to withstand the pick force of the printer. The two materials must be thin enough for the sheet to lie flat in the paper tray. The differences in thickness may cause the materials to curl down toward the leading edge of the form which can negatively affect feeding.

We recommend that the leading label edge should be thicker than the dual web overlap to make sure that the sheet lies flat in the tray. The label should be placed with the label facedown in the tray. Orient the label in the tray so that the pressure-sensitive area feeds into the printer first. The label should have no adhesive exposed in the overlay area or anywhere along the front or back of the label.

We recommend designing a non-adhesive strip with a minimum width of 1 mm (0.04 in.) along the edges of the overlay. To help prevent material from slipping in the fuser, we recommend knurling, which roughens up the exposed silicon area at the glue joint.

The face sheet of a dual web form is usually a paper pressure-sensitive product; therefore, the guidelines for paper labels are applicable to dual web forms.

The following diagram shows the recommended dual web form design. The non-print area may vary depending on the printer model.

A

Leading edge

B

Non-print area

C

Overlay

D

Paper

E

Pressure-sensitive

F

Non-print area

G

Reference edge

H

Stripped edge

I

Liner edge


Vinyl and polyester labels

Vinyl labels work well within specified design parameters. Vinyls are heat-sensitive, so the liners need to be thick enough to absorb excess heat and prevent melting. A total strip matrix may cause adhesive contamination. Thin liners or weak pull strength may lead to labels peeling off the label inside the printer, which requires printer servicing.

Materials, which have liner face melt temperatures lower than the fuser temperature, may require the leading and trailing edge stripped areas to be 1.6 mm maximum due to feeding problems. We recommend that the liner face is constructed with material that can withstand the fuser temperature, which eliminates changing the stripped areas from 3 mm to 1.6 mm.

When a 1.6-mm stripped area is used, it is very important that the 1.6-mm tolerance be held tightly. With a stripped area of less than 1.6 mm, it is highly possible that adhesive contamination will occur.

Vinyls are non-absorbing, which leads to toner buildup in the fuser that requires special maintenance. For more information about maintaining your printer, see the documentation that came with your printer. Vinyls may require a topcoat to ensure good toner adhesion. When you run vinyl labels, you may be required to install an oil fuser cleaner.

Polyester labels are less heat-sensitive but are also non-absorbing. Backings for polyester labels can be thinner, but requirements for coatings and cleaning are similar to vinyl labels.

Integrated forms

To create integrated forms, the converter uses hot melt adhesives to apply the label adhesive and liner to a base material (generally paper).

Oil bleed, recognizable by a discolored face sheet, can be a problem with these forms. Oil may also migrate from the top to the back surface of the liner while it is on the roll, before the conversion process takes place. The forms may be slick, and the pick mechanism of your printer may be unable to move all the sheets from the tray into the printer. Jamming and misfeeds increase when oil is present on the back of the liner.

The adhesive on these forms is commonly patterned on two or four sides (a non-adhesive border on either two or four edges). We recommend designing a 1-mm (0.04-in.) non-adhesive border (zone coated) on all four edges.

When printing on integrated forms with a grain long base material, position the form in the tray so the paper portion of the form feeds into the printer first. Position the pressure-sensitive portion of the form toward the portrait left edge. For integrated forms with a grain short base material, position the form in the tray so the pressure-sensitive portion feeds into the printer first.

Due to the unique construction of integrated forms, you may experience stacking problems in the output bin. If you experience stacking problems with these forms, then contact your marketing representative.

Note:  Test some forms before purchasing large quantities.

Printing on labels

Print on full label sheets only. Sheets with missing labels could peel off during printing and result in a paper jam. Partial sheets can also leave adhesive marks on the printer and cartridge, which could void the printer and cartridge service warranties.

Do not feed labels through the printer more than once. Doing so may contaminate the cartridge and other components with adhesive.

Depending on your printer model and the number of labels being printed, printing labels may require special printer maintenance. For more information about printing on labels, see Printer-specific paper support .

Maintenance procedures

Note:  These procedures apply only to mono laser printers.

If print quality begins to degrade when printing on vinyl labels, then do the following:

  1. Print on five sheets of paper.

  2. Wait approximately five seconds.

  3. Print on five more sheets of paper.

To maintain printer feeding reliability, repeat this cleaning process every time you replace the toner cartridge.

Note:  Failure to follow maintenance procedures for your printer could cause jams, poor print quality, feeding problems, and fuser problems.

Duplexing labels

Labels are not typically duplexed because of their special construction. However, printing on both sides of the label sheet may be possible if certain design, construction, and usage guidelines are followed.

When developing a paper label for duplexing, the converter should make sure that the label is designed to protect against contamination or buildup. Contamination results in paper feed problems and jams.

We recommend the use of label sheets that have a non-adhesive border around the label area. Make sure that the release strength is enough to withstand temperatures of 225°C (437°F) and pressure up to 25 psi.

Use label ties as needed. These small uncut areas (approximately 1.6 mm or 0.06 in.) help stabilize the label sheet and prevent tearing at perforations and die-cuts during printing. Label ties also prevent labels from predispensing in the printer.

The slits and cuts in the labels expose the adhesives to the printer. For best results, position the label sheet so the slits and cuts are not aligned with the ribs in the duplex or redrive areas of the printer. Doing so eliminates any contact points between the label adhesive and the printer and prevents any adhesive contamination in the printer. For more information, see Primary rib pattern design guidelines for reference edge alignment .

Load label sheets with the label end first. Use grain long paper instead of grain short paper, which tends to curl easily.

If a converter develops a grain short label sheet for duplexing, then test the sheet first to make sure that it works satisfactorily.

Note:  We recommend testing any material with your application and printer before purchasing large quantities.

To use the duplex label application, you may be required to install a fuser wiper. The wiper allows the printer to print on both sides of paper labels. To determine whether your printer requires a wiper, see Printer-specific paper support .

Primary rib pattern design guidelines for reference edge alignment

Rib pattern for Lexmark C6160, CS820, CS827, CX820, CX825, CX827, CX860, XC6152, XC8155, XC8160

Rib pattern for Lexmark C4150, C4342, C4352, CS720, CS725, CS727, CS728, CS730, CS735, CX725, CX727, CX730, CX735, XC4140, XC4150, XC4342, XC4352

Rib pattern for Lexmark B2865, M5255, M5265, M5270, MB2770, MS725, MS821, MS822, MS823, MS824, MS825, MS826, MX721, MX722, MX725, MX822, MX824, MX826, XM5365, XM5370, XM7355, XM7365, XM7370