The gig bag that came with my travel acoustic guitar only has 5mm foam so I wanted to add some lightweight structure and padding without great expense.
After speaking with David from TunnelCore® and his associate Dave, I used 5mm TunnelCore® (Bunnings).
This product was easy to work with and the 3mm self-adhesive PVA foam (Clark Rubber) stuck to it really well. I did need to use a utility knife to cut it. I suspect the 3mm product would cut easily with scissors.
As I was really happy with the strength and versatility of TunnelCore®, I went a bit further than planned and used it to made a storage box for spare strings.
I used double-sided tape to attach the Velvert (Spotlight) to the storage frame. Again, the TunnelCore® took the tape really well.
Overall, although not perfect, I’m pleased with the outcome.
Many thanks to David Adin and Dave for their advice on using TunnelCore®.