If I had seen this posting BEFORE you trimmed all the squares - I would have suggested washing them - that way there are no unpleasant surprises later -
Unpleasant surprises "before" are annoying - after the item is put together - they are "disastrous"
Although I do think we overuse words like "disastrous" "horrible" "awful" etc. for some relatively trivial events/happenings/situations.
Looks like you found some nice fabrics.