Is glen plaid made of houndstooth?

Partly, yes. The four-and-four bands of a glen check produce the same broken twill texture as houndstooth, while the two-and-two bands read as fine stripes. The alternation of the two is what builds the big crossing squares.

What is the Prince of Wales check?

Glen plaid with a colored overcheck laid across it, most often a windowpane of blue or red. The name honors Edward VIII, who as Prince of Wales wore the Glenurquhart check constantly in the 1930s.

Side by side

Houndstooth vs Glen Plaid

Houndstooth and glen plaid are the two great twill colorwork patterns of suiting, and one literally contains the other. Houndstooth is a single repeating motif: a 2/2 twill woven in four-and-four color order, producing the pointed tooth shape edge to edge. Glen plaid alternates that four-and-four order with bands of two-and-two, building a larger architecture of crossing squares from the same loom logic.

Houndstooth

No. 013

2/2 twill · first documented 1800s

Glen Plaid

No. 034

2/2 twill, banded color orders · first documented c. 1840

The differences

Aspect	Houndstooth	Glen Plaid
Structure	One color order throughout: 4 dark, 4 light, in warp and weft on 2/2 twill.	Banded orders: blocks of 4-and-4 alternate with blocks of 2-and-2.
Visual rhythm	Even, all-over, aggressive at scale; no larger repeat.	A composed grid of large squares with houndstooth-like texture inside.
Scale of wear	Risky at large scale, classic at small scale (puppytooth).	Inherently large-scale but visually quiet, made for full suits.
Heritage	Shepherd's checks of the Scottish Lowlands.	Glen Urquhart estate checks of the Highlands, 1840s.

Which to choose

They are siblings from the same loom technique. Wear houndstooth when you want a single bold texture, glen plaid when you want pattern with architecture. The overchecked glen plaid, the Prince of Wales, remains the most pattern a business suit can carry without raising its voice.

Common questions

Is glen plaid made of houndstooth?: Partly, yes. The four-and-four bands of a glen check produce the same broken twill texture as houndstooth, while the two-and-two bands read as fine stripes. The alternation of the two is what builds the big crossing squares.
What is the Prince of Wales check?: Glen plaid with a colored overcheck laid across it, most often a windowpane of blue or red. The name honors Edward VIII, who as Prince of Wales wore the Glenurquhart check constantly in the 1930s.

Full entry: Houndstooth Full entry: Glen Plaid

Sources & References

1.Houndstooth, Wikipedia
2.houndstooth, Wiktionary
3.Glen plaid, Wikipedia
4.Edward VIII, Wikipedia