measurements

ABSOLUTE

fixed values

RELATIVE

relationships defined
by a series of relative measurements

72pt

6 picas

1 inch

25.4mm

the em

the en

the em dash

the en dash

lower case alphabet

used as a guide when setting type

90mm

78mm

the em

• relative unit 
• define basic spacing functions
• linked to size of the type
• defines:
  • paragraph
  • indents  
  • spacing

the en

half an em dash

There is NO relationship between the em and en and the capitals 'M' and 'N'

em          

en 

hyphen

—          

– 

-

same as the pt size of the type     

1/2 an em

1/3 an em

em          

en 

hyphen

—          

– 

-

pauses in speech

nested clauses and stand in for 'to' 
10–11 or 1975–1981

hyphenated words

'half-tone'

the pica

points, pixels, inches, mm

Pica

• measuring lines of type

• equal to 12 points

• 6 picas / inch

• 72 points / inch

pixels

relative meaurement

A pixel is a single square 'picture element' (hence pix-el),

A 10x10 image is made up of a set of pixels in

a grid 10 wide by 10 high, totaling 100 pixels.

How many pixels = 1pt 

?

depends on the resolution of
your image.

If your image is 72ppi (pixels per inch)

then one point will equal exactly one pixel.