Technical Help

Technical Help is basically set up to help answer or advise and show some of the most commonly asked questions or printing problems we come across.  This page is an extended version and an easily updated version of our 2010 Calendar.

We’ll keep updating this page as time goes on.  Also keep in mind these are problems or situations we’ve come across and may not apply to other printers.  We’re also very open to questions or suggestions.  We hope we can help.

Varnishing

Machine Varnishing is a standard procedure for most printers.  Varnishing is usually applied where bleed of a solid image bleeds off the page or where a large solid area is applied to the stock, basically where a printer would trim through a solid  part of a finished job.

Varnishes basically enable the printed areas to be protected from the outside world with a clear ink base layer.  This layer can be applied as a standard matt or gloss finish depending on the base stock or the desired affect.  Varnishes are applied to most business cards or large printed areas.  The main reason for varnishing is to prevent scuffing of the base ink, for example a solid on the back of a business would require a varnish to prevent the solid area from scuffing onto the card in front once being handled.  Different stocks react differently and so may require more than one layer of varnish.

Keep mind to get the best result out of varnishes it is always best to let each layer dry 100% before a new layer is applied, some stocks will react badly with varnishes and will take even longer to dry if the base coat isn’t dry.  24hrs is a normal period for ink to dry and be rehandled. The varnish layer mind you will eventually rub off until the ink layer is exposed.  The only way to prevent such problems occuring is to cellosheen / laminate the product.  Varnishes can also affect a colours finish.  If PMS / Pantone Reflex Blue is the base colour and varnish is applied over the top, the varnish removes/hides the red/reflex part out of the colour.  The same goes for most colours.  We find with black when it dries it turns a slight brown black, once a varnish is applied the black turns more a blue black which would be the prefered black.

Generally Matt varnish is for uncoated stocks, Gloss varnish is for coated stocks.  Applying a gloss varnish to an uncoated stock once printed will normally highlight the fibres in a stock and so a solid can look a little more shinier.

Left side / majority matt varnished.                              Left print is unvarnished, Right is varnished.

Screen Percentages

One of the hardest issues with uncoated stocks is working out percentages and how they’ll look once applied to paper.  On screen you can’t see a 5% screen, but once the plate is burnt and on the press it’s actually quite clear.  The same with 95% of a colour, this pretty much looks 100%.

Screen ruling can play a serious role.  We use Stochastic screen ruling which comes out with a sparatic dot as opposed to traditional 200 line screen – both cost the same to output.  Stochastic seems to print up to 10% darker in the mid tones.  This can also be heavily affected by the amount of ink on the press.  If you want heavy ink application then you’re percentage can increase up to about 20%., the same for 200 line screen.

Photos can be difficult as well.  Depending on the image the more contrast the better, photos can print quite dark, the more grayscale/midtones in the photo the flatter/murkier the print will be.  If this is the affect you want then that’s fine.

Screen rulings

Screen rulings can play an interesting part with offset.  200 line screen is generally a great high screen ruling producing a clean sharp print on all stocks. Percentages out of colours though tend to show up so on a thin Swiss font at 50% out of black won’t look super smooth/sharp.  200 line screen also shows the full impurities of a graphic image.  Stochastic on the other hand hides some of these problems.  Not a commonly used screen but generally has better results for percentages and lower quality images.

200 line screen                                                                  Stochastic line screen

File Preparation

Spot Colour printing can be difficult when it comes to file preparation.  All trim marks, logos, text and images need to be setup as the specified PMS colour/s that you require.  If part of that file isn’t selected for the specific PMS colour plate image setter simply won’t output that part of the file.  Most of these errors are found before proofing but proofs should always be checked very carefully no matter who’s printing the job.
If a PMS colour has been chosen and the plate has been output you are still able to  change the PMS colour.  The press operator will be the one to put the right ink in the press.

Crop marks (AKA trim marks) are always required for files. Crop marks are used for image registration, squareness of the print on the paper, lining up forme cutting, embossing, foiling, Spot UV, letterpress and for cutting the final job down to size.

Press sheet layout

Taylor’d Press Business cards press sheet showing how we print business cards on an oversize A4 sheet.  4 different kinds, fronts on the left, backs on the right.  These are about to be triplexed, as you can see there’s a score line going down the middle of the sheet enabling them to be folded and have the “triplex” sheet inserted before being glued.  The grain direction is short grain which means its running along the short edge/side of the sheet giving the cards a firmer feel once trimmed.  This setup is the same for any 2 sided business card.