Thank you all for the welcome ..
No , if you cut them with kitchen scissors (Idid) no sharp edges unless you get tags , those you can trim ,
Also doubling the plastic one over the other , further reduces sharpness of any plastic being thin .
Disadvantage is over time outside the glue may turn orange .. might , it is made from foam insulation technology , but it's good..
The advantage is the soda bottle , water bottle plastic , does not break down from weather ..
Here's small one used in starter pots (wintersow) and a 1/4 round for the garden with the one shown before .. These are a 2 liter , water bottles are thinner only as to shape ?'s are often as easy and durable ,