Good quality sew-on snap buttons in various sizes.
eBay
40pcs 14mm Magnetic Button Clasps Set - Metal Snap Fasteners for Sewing, Crafts, Wallets, Bags, Clothes, Leather
Aliexpress UK
If your leather is too thick. Firstly, wet the leather and line up the stud parts with the hole. Press the stud into the leather to make an impression, allow leather to dry. With your knife tip pointed into the centre of the hole and laying flat against the impression, turn the leather and/or knife in a circle and gouge out a perfectly round recess into the leather to give extra depth.
eBay
Easy-Attach 14mm Magnetic Snap Buttons - 40 Set Multi-Color Pack for Sewing and Crafts, Durable & Stylish Metal Fasteners
Aliexpress UK
15mm S Spring Press Studs Snap Fasteners Plastic Cap No-Sew Snap Buttons Tools. 12.5/15mm Flat Cap Press Studs Sewing Leather Craft Clothing Snap Fasteners. 4 Parts Press Studs Snap Fasteners for Buttons Poppers Handbags Purses Coats.
eBay
Snap Button Kit with Hand Pressure Pliers 50pcs Snaps Metal Snaps for Sewing Sewing Snaps for DIY Crafts Clothes Hats Sew Tool
Aliexpress UK
4 Parts Press Studs Snap Fasteners for Buttons Poppers Handbags Purses Coats. 10/12.5/15mm S Spring Press Studs Snap Fasteners Popper Buttons Leather Coats. 15mm S Spring Press Studs Snap Fasteners Plastic Cap No-Sew Snap Buttons Tools.
eBay
20 Sets Marine Grade Twist Lock Fasteners Turn Button Eyelet and Stud, for Canvas Fastener Turn Buttons
Aliexpress UK
100 Sets Heavy Duty Poppers Snap Fastener Press Stud Sewing Rivet Craft Clothing. Silver Large S Spring Press Studs Snap Fasteners DIY Clothing Bags 12/15/17/20mm. 4 Parts Colourful Cap Press Studs Snap Fasteners Handbags Clothing Jacket 15mm.
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Metal Snap Button 15mm 18mm 21mm Clasp Buttons Hollow Flower Invisible Coat Buttons Fashion Suit Buckle Black Gold Silver 5piece
Aliexpress UK
201PCS Prong Pliers Ring Press Studs Snap Popper Fasteners 9.5mm DIY Tool Kit UK. 200 x 9.5mm Prong Ring. Perfect for Baby Grows, Keyrings, Shirts and Jeans, Jackets, Bags, Bandanas, Nappies, Bibs or other general arts and crafts.
eBay
20 Sets Marine Grade Twist Lock Fasteners or Canvas Fastener Turn Buttons Eyelet and Stud
Aliexpress UK
Magnetic Snap Fasteners for Leathercraft Closures: Enhance your sewing, crafting, and leather projects with our 14mm / 18mm laser-cut magnetic snap fasteners. Ideal for handbags, purses, jackets, and DIY bag repairs, these no-sew magnetic closures provide strong yet invisible fastening solutions for stylish and functional designs.
eBay
20sets/lot 10mm-18mm Magnetic Buttons Bags Clasp Snaps Magnet Automatic Adsorption Thin Wallet Button DIY Sewing Craft With Box
Aliexpress UK
Practical Tool: Pliers is easy to use, suitable for mounting hollow or solid prong buckle. Premium Material: The snap fasteners are made of copper, durable, with harmless to the human body. Color: red, black, pure white, orange, grass green, dark pink, royal blue, light purple, light yellow, light blue.
eBay
10 Sets Magnetic Snaps Button,Metal Round Magnetic Clasps Button Fabric Base Components and Cap Kit Diameter 14mm / 18mm
Aliexpress UK