Glulam has many more possibilities than just the visible wood look, lacquered or untreated. If you treat the glulam surface it can take on a new form or look. A dramatic black top coat, a whitewash or silky gray steel are just some examples of finishes that both protects and enhances the look of your glulam.
Glulam ages beautifully, but it does so best when the surface has been treated, both indoors and outdoors. You can surface treat glulam using the same means and methods used for ordinary wood. What you choose depends more on how you want it to look like and what protection surface treatment you are looking for. Impregnated glulam provides effective protection against rot but must be treated and maintained in the same way as normal glulam.