Colour and Typography in Maps Questions and Answers

Answer: A

Red, green and blue light overlapping at full strength give white, which is why every screen uses the model. Ink works the other way about, removing wavelengths from the light reflected off the sheet, so printing needs a different model entirely.

Answer: B

Correct answer: absorbs part of the light striking the paper

Ink on paper works by removing wavelengths from the light reflected back, so each ink subtracts and the more inks laid down the darker the result. A screen works the other way, adding coloured light to black - which is why the two use different primaries and why one cannot reproduce everything the other can.

Answer: C

The key plate carried the fine detail to which the coloured plates were registered, and it was printed in black. Using K rather than B also avoids any confusion with the blue of the RGB model, which matters when a specification names channels by their initials.

Answer: D

Correct answer: False

The two gamuts overlap but neither contains the other. A screen produces saturated greens and blues that no combination of process inks can reach, while some deep yellows print better than they display. Every conversion from screen to press therefore involves choosing substitutes for the colours that fall outside.

Answer: A

Every screen, press and paper combination can produce only part of the visible range, and the parts differ. A colour outside the target gamut must be replaced by the nearest one available, which is what makes conversions lossy.

Answer: B

A pre-mixed ink laid down on its own gives an even, exactly specified colour, which suits a map with a small palette. Process colour builds shades from four screens instead and is the choice when the sheet carries photographs.

Answer: C

Dots too small to resolve individually blend with the white paper between them, so a 20 per cent screen reads as a pale tint of a full-strength ink. The ink itself is never weakened, which is what keeps the colour consistent across every tint of the same plate.

Answer: D

A percentage screen names the proportion of the area covered by ink, so 40 per cent gives about four-tenths of the full strength. The relationship is close to linear in coverage, though ink spread on absorbent paper darkens it a little.

Answer: A

Correct answer: False

Ten per cent is close to the limit of what a reader can judge on a printed sheet, and quite beyond it when the two tints are not adjacent. Steps of twenty per cent or more are needed for classes to be told apart reliably, which is one reason a choropleth map should carry few classes.

Answer: B

Both are true and the reason gives the mechanism: separated patches force the reader to carry a shade across the sheet, and small differences are lost in the process. Adjacency turns a difficult judgement into an easy one.