Printing on Rockstock

Printing Rockstock

Printing Considerations: Rockstock RPD-RBD.

See video of a Heidleberg Press printing stone paper!

NOTE: USE STANDARD INKS-No special inks are required

Rockstock can be printed through most printing methods, which includes:

offset-(Water Offset, Dry Offset, and UV Offset)

Letterpress (rotary and sheet-dry and UV)

Flexography,(Water Flexo, Solvent Flexo and UV Flexo)

Roto-Gravure (solvent, UV and water based)

Serigraphic

Ink Jet: UV ink Jet , Flat bed, Solvent, flat bed ( a test may be required to ascertain the correct stock type.: HP Indigo WS6600  (for Rocktak) and some other low temperature machines.(Testing is required)

Xerox 550/560/1000  (testing required) with low temperature settings

Xeikon Digital 3030-8600 (testing required)

The Stone paper Company cannot be held liable for any damage  or loss  caused when running Rockstock on any printing equipment. It is the responsibility of the printer to test or check heat ranges before running Rockstock. The maximum operating temperature of Rockstock or Rocktak should not exceed 140 degreesC.

NOT SUITABLE FOR HIGH TEMPERATURE LASERS AND PHOTOCOPIERS.

(Guide for Offset printing below)

(Please note the following is only a guide. Settings may be different depending on printers, presses and operators.)

1. Regular and soy inks are adequate for printing on RPD and indications are that in many cases less ink is required.(depending on stock compared, amount of solids, press type, process etc.) do not add hardeners or driers)
2. Printing speed is approximately 7500 ~ 8000 sheets per hour for dark / solid colour, more than 9000 sheets for lighter colours.
3. Water feed is [Set 21 and Ratio 115].
4. Ink feed is [Set 40 and Ratio 116].
5. Drying powder is level 4~6, depending on artwork.
6. RPD's surface quickly dries after print. For RPD to be fully dry and ready for further prints or processes please allow approximately 1 hour after light colour prints or 12 hours after dark colour prints. Please note that drying agents can be added to the ink to shorten the drying time.
7. It is recommended to  turn off Infra red Drying units as heat may distort or curl the sheet.
8. When stacking printed paper, please place separating plates as required especially when there are large solids.
9. To minimize static, please maintain at least 40% relative humidity. Anti-static equipment such as ionizing air units at feeder and/or delivery is preferred but not essential.
10. Please trim 4 sides of the paper especially to ensure higher printing and converting precision.
11. We would encourage Graphic artists and printers to include the No 2 Recyle logo on printed pages and items to encourage recycling of Rockstock, as Calcium carbonate is a useful additive in the plastics recycling stream. A message about the clients contribution to a better global environment by using Rockstock is also a worthwhile addition.
12. Rockstock RPD is ideal for creasing, diecutting, Hot and cold foiling and embossing. lamination, glue binding, punching, pre cut holes, roll slitting, perforating, additional print passes and numerous other processes (The surface will not 'crack' when folded and will not weaken with use- Ideal for maps, brochures & and charts. The ink will not 'white line' on the fold.)
13. RPD100 is not recommended for sheet fed as feeding problems or low press speed may result. It is also not recommended to print large solids on RPD weights below RPD160 micron as unflattened sheet may result when ink dries, especially RPD100.
14. When Embossing Heat applied to the embossing die/s will enhance the embossing performance of Rockstock as the thermoforming ability will ensure the best outcome.
15. Rockstock RPD has a matte feel and finish. If required, it can be overglossed, UV overglossed,  or film laminated to enhance the finish to prevent ink wear and "chalking". Because of Rockstock's inherent strength it is not necessary to film laminate to add strength. However if a laminated finish is required, this works well.
16. Turn off Infra red Drying units. Most UV drying units are okay.
17. The coating on Rockstock RBD (card) is not quite as waterproof as that of the RPD (paper). It is recommended that if a total waterproof requirement is to be achieved that a coating, overgloss, UV overgloss, seal or lamination be applied. ( Much work is being carried out to improve the coating. )

FREQUENTLY ASKED QUESTIONS (FAQ)

We recommend you to test print the paper, understand its strengths and weaknesses
well before using Rockstock. This is to ensure problems, if any, are resolved in the early sampling stages.

The following are some points which you should familiarize yourself with as they are considered normal qualities of the paper.
Q: Is there whiteness variation?
A: For environmentally friendly reasons all stone paper products are 100% free from
bleach. As bleach or optical brighteners are not added, this means that slight variation in the whiteness between different thicknesses and batches can occur. This is normal.

Q: What is rubbing resistance / rubbing effect?
A: Via normal offset printing methods, rubbing the printed matter against the paper
itself may result in colour offsets. This is normal. Special ink ,overgloss, sealing,  coating or extra converting procedures (e.g.film laminating)can be performed to reduce or eliminate this.

Q: What is the accepted thickness variation?

A: RPD: thickness variation of up to ± 5 microns.
RBD: thickness variation of upto ± 6 microns
Particularly when printing solid colours, colour differences may be visible due to the
thickness variations. However with continued quality development these normal variations are expected to reduce.

It is expected that thickness variation will further reduce to 3-4 micron with the commissioning of new and enhanced paper machines.

Q: Is set -off a problem?

A: Rockstock can be treated much like usual paper stocks. Especially with boards it is recommended to use small stacks or racking in the delivery especially when large solids are printed. Anti-Offset Spray Powder can be used as per normal. If the press has Infra Red Drying Units (IR) then these should be turned off as the tail end of the sheet may curl or distort with heat, especially with papers (RPD). Another benefit is that power usage is reduced.

Q: Is stone paper less opaque?
A: Due to inherently different materials, compared to pulp paper, stone paper is
generally more transparent although a new coater recently has considerably improved opacity to 88%.

Q:Can Rockstock be used in a laser printer or photocopier.

A: Rockstock is not suitable for Laser Printers or Photocopiers where high heat is generated as this may distort the sheet and cause jamming. Low temperature Digital presses with operating temperature below 140 degrees C that may print on Rockstock  include. HP Indigo6600 HP , HP Indigo Jet Pro UV (wide format), Oce UV wide format, Ricoh 710c , Zerox 1000, 550/560 all with lower temeratue settings.

Q: Will I get paper cuts with Rockstock.

A: No, it is unlikely to give you paper cuts because of its flexibility and its fine powder structure.

On request printing guidlines and information is available.