Tyvek is a paper which bubbles and distorts with heat, but is difficult to stitch through once heated. Tyvek is non porous so really has to be coloured both sides, otherwise when the sides distort and roll in you will have the white backing showing.
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ESHANG 5 Sheets Matte Printable Magnetic Sheets 8.5" x 11"Flexible Magnet Sheets Non Adhesive for Photo and Picture Magnets
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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Japan KOKUYO Staple Free Stapler Harinacs Press Creative & Safe Student Stationery For 5 sheets or 10 sheets
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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10 Sheets DIY A4 Inkjet Waterslide Decal Transfer Paper White Clear Laser Waterslide Decal Paper Sheet for Inkjet Laser Printer
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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50pcs Heat Resistant Clear Acetate Sheets, 11x16cm PVC Transparent Plastic Sheets for DIY Scrapbooking Handmade Shaker Cards
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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Heat Resistant Clear Acetate Sheets 5pcs/lot Plastic Window Sheets for DIY Scrapbooking Shaker Cards Hot Foiling Project
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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10 sheets A4 size glossy printable vinyl sticker paper for inkjet printer self-adhesive sheets 8.3 "x 11.7"
Aliexpress UK
Best of all, No tools are required. DuPont Tyvek.
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A4 Size 8.3x11.7 (Pack of 5) 3mm Adhesive Magnetic Sheets for Magnet sheets with Self-Stick Adhesive for Home Office,Easy Cut
Aliexpress UK
Place the Tyvek between 2 Teflon sheets and iron lightly and the Tyvek will bubble and distort. Allow to cool before removing from the Teflon. Cut your Tyvek with ordinary scissors (it is virtually impossible to tear by hand) and then colour it on both sides - do one side and allow it to dry before turning over to do the second side.
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A4 20 Sheets Diamond Holographic Sticker Paper for Inkjet & Laser Printer Waterproof Clear Vinyl Sticker Sheets Self-Adhesive
Aliexpress UK