Rymans are cheaper for gift bags. I keep a fair stock and re-use them as many times as is practical. This does involve some subterfuge to retrieve the bags at times.
Surely there's some kind of spray-on wrapping paper available these days? What are these so-called "scientists" doing all day if they're not inventing stuff we need? Arguing about God?
Just tell them you've come to the conclusion that disposable wrapping for gifts is ecologically unsound, so to save the planet you're going to put them in pillow cases from the airing cupboard.
I use newspapers which are going to be recycled anyway, or one of the many rolls of unbleached brown paper lying about my loft. Much easier to recycle than glittery stuff.
When I bought my father a shedload of airfix kits for christmas I wasn't going to wrap them individually so I got there early to lay them out in his workshop and popped a wrapping paper hood on him just before leading him through the door. The effect was the same and it must have saved at least three or four rolls of paper.