Phone Photos, a Web Logo, and a Four-Colour Black Request
An A4 four-page folder is to be printed 4/4 on 170 gsm matt art paper at 175 lpi. The client supplies: six smartphone photos, the smallest 800 x 600 px, which the designer has placed 180 mm wide on the cover; a logo grabbed from a website as a 600 x 200 px JPEG, placed 60 mm wide; body text set in 8 pt in a four-colour build of C60 M40 Y40 K100; and a request for a 'rich deep black' background behind 7 pt white reversed text. All files are RGB, untagged, and some were saved from WhatsApp. The client wants a 'colour-accurate' proof by Wednesday and says the last printer 'made the skin tones too red and the black grey'. The shop has a calibrated inkjet proofer and a spectrophotometer, and prints to an ISO 12647-2 type profile.
1. Calculate the effective resolution of the 800 x 600 px photo at 180 mm wide and the logo at 60 mm wide. Decide what to accept, reject or resample, and what to tell the designer.
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For the photo: 180 mm = 7.09 in, so 800 px / 7.09 in = 113 ppi at the placed size. For 175 lpi, the usual requirement is about 300 ppi at final size; even the 2x rule gives 350 ppi. The photo is therefore far below requirement. The maximum width at 300 ppi is 800 / 300 = 2.67 in, about 68 mm. So the photo must either be reduced to about 68 mm wide or replaced with a higher-resolution original.
For the logo: 60 mm = 2.36 in, so 600 / 2.36 = 254 ppi. That is below 300 ppi but a logo is line art, so the better answer is to obtain a vector EPS, AI or PDF rather than resample a JPEG. At 254 ppi a clean logo may survive, but a web JPEG usually has compression artefacts and no transparency, so replacing it is safer.
Do not upsample the 113 ppi photo to 300 ppi and call it fixed; interpolation adds pixels but not detail. Tell the designer the exact placed sizes that work, request original camera files rather than WhatsApp copies, and ask for vector artwork. Record the acceptance decision on the job ticket so the client cannot later blame print quality on the shop.
2. What is wrong with the 8 pt text set in C60 M40 Y40 K100, and how would you handle the 'rich deep black' background behind 7 pt reversed text?
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C60 M40 Y40 K100 is a 240% four-colour build, not a text black. At 8 pt, any registration variation between the four units produces coloured fringes, and the total ink coverage can exceed a safe limit on matt art paper, causing poor drying and set-off. Small text should normally be printed as 100K only. If a richer black is wanted for visual weight, it should be a controlled build agreed with the press, not an arbitrary 240%.
The reversed-text request is riskier: a heavy four-colour background behind 7 pt white type can fill in the counters, especially if ink is over-applied or registration moves. Specify a controlled dark background with a stated total area coverage, for example C40 M30 Y30 K100 at 200%, and keep the black under control. Use a typeface with open counters and slightly heavier weight; avoid hairline serifs. Check the reverse at 100% on the contract proof under correct lighting. If the client insists on maximum black, propose a solid black panel with the white text kept away from the heaviest ink area, or print the text in a light colour on a separate panel. The decision balances appearance against legibility and press capability.
3. How would you produce a colour-accurate proof and manage the client's expectations about skin tones and the black?
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Start by converting all RGB files to the shop's CMYK profile for the specified paper and ISO 12647-2 condition, using relative colorimetric rendering with black point compensation. Do not convert each image with different settings. For skin tones, correct selectively with hue/saturation and curves, using the CMYK numbers as the reference and checking that magenta and yellow are not pushed equally, which is what made the previous job too red. Use the calibrated monitor only for soft proofing; the contract proof must be made on the calibrated inkjet with the same profile and measured with the spectrophotometer.
Show the client a printed reference and explain that a phone screen is emissive RGB and cannot be matched exactly. Label the proof as a contract proof for the specified paper and ink set, and get a signature. Explain that the 'deep black' will be a controlled rich black, not 400% ink, because 400% would set off and fill in the 7 pt reverse. Offer a press sheet from a similar job as a visual aid. If the client still wants a different black, quote a second proof rather than changing the job after plating; this protects both the schedule and the colour responsibility.