Hi Kwan,
Thank you for taking the time to leave us this lovely feedback :)
For a more robust sticker I would recommend going for our heavy duty material (https://stickerit.co/heavy-duty-stickers/?materialSku=heavy-duty#pc)
This is 8x thicker than our other stickers and has a stronger adhesive.
I hope this helps and if you have any queries feel free to drop me an email at info@stickerit.co :)