These are muntins installed by the manufacturer of insulated glass inside the glass chamber. This is currently the least often chosen form for division of glass panes. Inter-pane muntins are manufactured in thicknesses of 8 mm, 18 mm, 26 mm and 45 mm. These muntins are available in different colours and in an imitation wood variant.
Their main advantage is that they does not require maintenance and cause no problems during cleaning, as they are placed inside the window. The downside is that it is visible that the muntins are made of a material other than wood. Furthermore, they cannot be removed once windows are in use, as this would entail exchanging the whole glass pane set, which is costly.
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