The quantity required always depends on the type of tent cloth. For example, a cotton folding trailer tent will require less impregnating agent than the tent cloth of a safari tent.
Below is a rough guide.
1L bottle = treats 5 to 10 m²
We advise impregnating canvas, cotton or linen tent cloth while it is under tension. By pitching the tent, the cloth is slightly stretched. This creates minuscule holes. These holes may cause the tent to leak over the course of time and cause the tent to become damp on the inside.
Thus, it is preferable to pitch the tent before you impregnate it.