There have been a lot of submissions for plastic laminate spacers – from wood dowels to newspapers. Anything that can leave any material behind to get trapped underneath the laminate will cause either a bump or a non-adhered spot and may require complete removal.
Wood dowels can leave splinters. Newspaper can stick and tear if there is just one sticky spot. So my spacer of choice is the thin shelf standard. I use the (KV) aluminum that is less than 1/4 inch high and about 1/2 inch wide. another advantage is the “U” shape that contacts just its outer rails on one piece.
In the “old days” with solvent-based glue, there might be a spot where the standard will stick – however these are strong enough to pull HARD without breakage, splintering or tearing.