MyPrintingTutorials.com-Printing Tutorials Offset Printing Digital Printing A Guide to Offset and Digital Printing

We recently purchased Ricoh’s black and white entry level copier cum printer Ricoh Aficio MP 1600L. The price of the machine was around Rs. 70,000/-. The cost per page including drum and developer changes cost for an average A4 size document with around 5 percent coverage comes to around 32 paise (Rs. .32/-). This is excluding the cost of paper. An average A4 size copier paper costs around 30 paise or less depending on local prices. The maximun printing size is A3. The drum and developer have to be changed at around every 70,000 impressions. The cost of the drum and developer comes to around Rs. 8000/-. The machine gives very clear and fine prints of text. Photo quality is also not bad. The cost per page is very minimal compared to a black and white laser printer. As a printer we are also using it for technova offset master printout. Toner scatter and other problems start to increase as the run length comes around 70,000. That is when we have to have a complete servicing and change the necessary parts.

Posted under Digital Printing

From the same manufacturer of mug printing machine comes this multi utility printing machine. The process is the same as for mug printing except that the machine is now a flat press instead of the rounded one for mug printing. It can print on even more media and items not mentioned here and they are continuosly coming up with new items which can be printed upon using this machine. The price of the machine comes to Rs. 35,000/-. The printer comes for Rs. 7,000/- and the CISS ink system comes for Rs. 5,000/-. The cost of printing on one t-shirt comes to around Rs. 20/-. The printing is complete multicolor.

Posted under Miscelleneous

During the Print Pack 2009, I came across a fascinating mug printing machine. A special type of transfer paper is first printed using an epson printer which uses dye inks. Then the mug which is specially treated for the purpose of printing on it is placed in the mug holder along wiht the paper wrapping it. The holder is capable of passing heat on the mug which causes the print to be transfered to it (mug). The whole process is simple but the prints are excellent. The only drawback could be that it can print on only one size of mug and that also on only the specially treated mugs availble from the company. I don’t remember the name of the manufacturer right now but wil post it as soon as I go through my files. The price of the mug printing machine along with the printer and the ink system was around Rs. 37,000/-. The price of printing one mug comes under Rs. 10/-. I could not enquire the price of the mugs.

Posted under Miscelleneous, Uncategorized

During the recent Print Pack 2009, Autoprint displayed their new innovation – the Dion 450, a four color printing machine from Autoprint’s own stable. The Dion 450 is a single crown size (15″x20″) printing machine. It is not so automated like other imported machines in India as automation is not so necessary here compared with the additional cost that will fall upon the machine price. The machine comes with the Kompac dampening system on all four units and a powder spary at the delivery end. There are sensors to stop the machine in case of paper jam on any of the blankets. The whole machine is pneumatically controlled and there are no levers for the inking or dampening process. The printing quality is quite nice and with some training any experienced operator should be able to run the machine with ease. On the whole, I would say it is a very good machine with respect to its price and performance ratio. The basic price of the machine is 33,00,000 (Thirty three lakhs).

Posted under Offset Printing

Technova is expected to come out with its own CTP (Computer To Plate) which will cost around Rs. 55,00,000 ( Rs. 55 lakhs) very soon.

Posted under Pre press

Digital Printing has become a very profitable business especially when you have to print in small quantities. Digital printing could mean inkjet or laser printing. As for now the benefit in cost is in laser printing. At the lowest end will be the color laser copiers that are being sold in the market by various manufacturers. At the high end will be the digital production printers offered by companies like Hp and Xerox with printers like the Hp Indigo and the Xerox iGen4. The Hp Indigo starts from about Rs. 8,000,000/- (Eighty Lakhs or Eight Million Rupees). For small printers the Digital presses like Xante Illumina, Xitron Prism and the Xerox DC242 may be more feasible. The Xante Illumina and the Xitron Prism comes under Rs. 800,000/-. The Xerox DC242 starts from Rs. 1,400,000/- (Fourteen lakhs). All these printers print 12″x18″ size paper. The cost per page come around Rs. 8/- irrespective of ink coverage under the company policy where we have to give this amount to them. The cost of digital paper comes to about Rs. 3/- per 12×18 inches sheet. These small digital printing presses are suitable in India for only around maximum 200 tabloid pages per job because the cost of offset color printing is very low here. However for small repeat jobs they are very profitable. The quality of the color copiers at a lower range are not that acceptable for a print shop.

Posted under Digital Printing

The three roller Kompac Dampening that we use in our Autoprint machine has taken our color printing at another level. Printing of solids and other complicated jobs proved to be quite a disaster previously. The conventional dampening with cloth is not at all advised while going for color. This dampening causes huge color shifting from sheet to sheet and scum is also a problem. The Kompac II with the color mate removes these problems. As for now we don’t have any scum problem in the printing and sheets dry quicker. Color shifting from sheet to sheet has also been greatly reduced and we don’t have problem printing of solid areas even though our machine has only two ink form rollers. The stress that the machine operator used to have has also been reduced. Now there is quick ink and water balance in the machine. The dampening system is compatible with all Autoprint 15×20 machines. The price from Autoprint is around Rs. 120,000/-

Posted under Offset Printing

Dot gain is a phenomenon that happens when the size of a printed dot increases during the printing process. This cause the quality of the final printed matter to be distorted with respect to color. To a large extent this can be controlled after careful monitoring of the whole process of printing. A densitometer will be required to predict dot gain more accurately. Dot gain is controlled better in a CTP process than in a film to plate process. During plate exposure and processing there can be dot loss instead of dot gain if the plates are over exposed. In the Technova Polyjet system there can be dot gain or loss in the film if the ink density adjustment is not accurate in the Epson printer. At our press we use a ink density setting of 40 percent for 1440×1440 dpi at 125 lpi using a linearization file for 125 lpi.

Posted under Offset Printing

After a file has been designed and completed, it is to be saved in TIFF format in Photoshop at 300 dpi in CMYK mode for commercial printing. Various profiles may be used to reduce dot gain in printing. For web offset printing 150 dpi may be sufficient though some web offset printing may go up to even 250 dpi. Dpi (dots per inch) as a rule has to be about twice the lpi (lines per inch). Sheet fed offset printing is normally done in 150 or 175 lpi. Therefore it needs about 300 dpi files. Web offset on the other hand is done in about 75 lpi to 100 lpi so they may need only about 150 to 200 dpi files. However all files have to be in CMYK mode.

Posted under Offset Printing

Most commercial printers print at 300 dpi which is suitable for 150 to 175 lpi. So in order to get a photo printed at 300 dpi the final resolution of the photo after resizing should not be less than 300 dpi. When you resize a photo after scanning the dpi increases or decreases depending on whether the photo is scaled down or scaled up. That is unless you re-sample the photos in Photoshop by clicking the re-sample button. Re-sampling up is not advised unless absolutely necessary and even then the photos should not be re-sampled up more than 10 percent otherwise the quality will deteriorate. Re-sampling down is alright but should be done after the image has been finally edited.

Now if suppose a 7×5 inches photo is to printed at 300 dpi then we have to scan the photo at 300 pixels per inch. However if the photo is to be enlarged to 14 x 10 inches then 300 pixels would not be sufficient as when the size is increased the dpi will go down, in this case, to 150 dpi. So in order to maintain the same dpi the pixels have to be increased. A 14 x 10 inches photo at 300 dpi requires 4200 x 3000 pixels (14×300 = 4200, 10 x 300 = 3000). To get this pixels the 7 x 5 inches photo has to be scanned at 600 pixels per inch ( 4200/7 = 600, 3000/5 = 600).

As a rule when the photo is going to be resized at twice the length and twice the breadth the pixels have to be doubled. So scanning resolution of 300 ppi becomes 600 ppi when the length and breadth of the scanned picture are to be doubled.

Posted under Digital Printing, Offset Printing