Standard is 10 cm high at the longest point of the word/letter. So any capitals and "q, t, y, p, d, f, g, h, j, k, l, b." will be 10 cm high. width varies greatly per font but roughly standard pieces are between 3 and 5 cm wide per letter.
How big are the XL pieces?
XL pieces are 20 cm high and they are made from a thicker 4 mm wire. They look more effective if only for a small quote or name.
How do you attach them?
The wall mounted pieces or custom pieces require holes to be drilled into the wall. At the start and the end of each letter or word (font depending) there is a right angle of wire which requires a hole to sit neatly. Standard needs 3mm holes and XL 4mm.
Each piece comes with Instructions but these can be found at the top of the home page.