I use them to block light paths in optical circuits. They have slightly reflective surfaces but are perfect for in-between experiments like covering light sources for spectrometry etc. I think you can use them for other purposes as well.
βοΈ Zoom Precision Brother ScanNCut 3-in-1 Etching/Engraving Tool - Precise, Standard, and Dull Engraving Tips with Heart, Dog Tag, and Circle Stamping Blanks for Brother Scan and Cut Machines
4 Review
π§ Dremel 290-01 Engraver Rotary Tool with Stencils - Ideal Crafting Machine for Personalizing and Engraving Leather, Metal, Glass, and Wood, 120V, Black
5 Review
2-Piece Metal Scribe Tool Set with Tungsten Carbide Tips - Engraved Pen for Glass, Wood, Ceramics, and Gold
4 Review
π₯ Afantti Electric Micro Engraver Pen: DIY Engraving Tool Kit for Metal, Glass, Ceramic, Plastic Jewelry - Scriber Etcher with 30 Bits, 8 Stencils
4 Review
420 PCS Mini Natural Chip Stone Beads 3-5Mm - 7 Chakras Gemstones Healing Crystal Loose Rocks For DIY Bracelet Jewelry Making Crafting
32 Review
EuTengHao 1100Pcs Irregular Chips Stone Beads Natural Gemstone Beads Kit With Earring Hooks Spacer Beads Pendants Charms Jump Rings For DIY Jewelry Necklace Bracelet Earring Making Supplies
26 Review
Hedi 6Mm Purple Color Pearl Beads Rosary With 6Pcs Our Rose Our Facther Beads
31 Review
Aquabeads Beginner Arts & Crafts Bead Kit For Kids - 900+ Pieces Carry Case Set
26 Review