Quick answer: Black Printing Borosilicate Glass covers Borosilicate Glass (CTE 3.3 x 10^-6 /K, 360 nm – 2.0 um); OD > 4 masking, windows to +/-0.1 mm. Prototypes ship in 5-10 working days.
The point of black printing borosilicate glass is simple: opaque bezels, icons and IR windows on covers. We deposit it by screen print + 620 C firing onto Borosilicate Glass and verify OD > 4 masking, windows to +/-0.1 mm on every lot.
Key parameters
| Material | Borosilicate Glass (3.3 expansion group per ISO 3585) |
|---|---|
| Thermal expansion (CTE) | 3.3 x 10^-6 /K |
| Service temperature | 450 C continuous |
| Transmission range | 360 nm – 2.0 um |
| Density | 2.23 g/cm3 |
| Knoop hardness | 480 kg/mm2 |
| Refractive index | 1.473 @ 587 nm |
| Stock thickness | 0.50 – 30 mm |
| Maximum blank size | 600 x 400 mm |
| Treatment | Black Printing – screen-printed ceramic ink |
| Specification | OD > 4 masking, windows to +/-0.1 mm |
| Deposition / method | screen print + 620 C firing |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Design guidance
The shop-floor rules that matter here:
- Material note: sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step.
- Sequence matters: all machining happens before black printing; post-coating rework is not economical.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
The full rules live in our tolerance design guide and holes and edges design guide.
What the process holds
Beyond this page, Borosilicate Glass routinely runs through polishing, ultrasonic machining, double-side polishing, dicing in our shop – most real parts combine two or three of these steps.
Application context
black printing borosilicate glass shows up across medical diagnostics (flow cells, slides, microplate bottoms, cuvette windows); scientific instruments (reference flats, cells, prism mounts, stage inserts); laboratory instruments (cuvettes, sight glasses, stir-cell windows). Background reading on the underlying material science: ISO 3585 borosilicate glass 3.3.
The fastest route to a quote is geometry: use the 3D builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Engineers scoping this work usually also review glass sandblasting, material selection guide, fused silica wafers 2-12 inch.
Buyer questions, answered
Is there a minimum order for black printing borosilicate glass?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
What files do you need for a quote?
A dimensioned PDF plus DXF or STEP geometry. If only a sketch exists, our drawing review service formalizes it before quoting.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
What tolerances are achievable on Borosilicate Glass parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step.
Specifications on this page were last reviewed by our engineering team in September 2026.