# Stencil Size Specifiation Outdated?

**URL:** <https://community.aisler.net/t/stencil-size-specifiation-outdated/5899>\
**Category:** ℹ️ Q & A Help Zone\
**Tags:** pcb-design\
**Created:** [September 17, 2026, 5:22pm UTC](https://community.aisler.net/t/stencil-size-specifiation-outdated/5899 "2026-09-17T17:22:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Joel1](https://community-cdn.aisler.net/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@Joel1](https://community.aisler.net/u/Joel1)\
**Post date:** [September 17, 2026, 5:22pm UTC](https://community.aisler.net/t/stencil-size-specifiation-outdated/5899/1 "2026-09-17T17:22:35Z")

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**Title:** Prototype stencil top margin is 22.7 mm instead of the specified ≥ 25 mm?

Hi,

I measured one of my prototype stencils (order 2026-77271, board outline 68.73 × 53.49 mm) to build a 3D-printed registration jig around it. I scanned the stencil on a flatbed scanner, and moved the apertures to my KiCad paste layer and measured the distance from the board outline to the stencil edges:

| Side | Spec ([Prototype Stencil Specification](https://community.aisler.net/t/prototype-stencil-specification/3412)) | Measured |
| --- | --- | --- |
| left | 15.0 mm | 15.05 mm |
| right | 15.0 mm | 14.89 mm |
| bottom | 35.0 mm | 34.87 mm |
| top | ≥ 25.0 mm | 22.72 mm |

Left, right and bottom match the spec nicely, but the top margin is 22.7 mm, not 25 mm or more. The total stencil height of 111.0 mm matches my calipers as well, so this is not a scaling issue with the scanner.

Measured from the topmost paste aperture instead of the outline, the top margin is 24.75 mm, so my guess is that the top margin references the paste bounding box while the other three reference the board outline. Alternatively the total height might be rounded to whole millimeters (111.0 mm here). Could you clarify which rule applies, so I can predict the stencil outline for future orders?

Thanks!

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<div class="post-metadata">

**Author:** ![Sarah-from-AISLER](https://community-cdn.aisler.net/user_avatar/community.aisler.net/sarah-from-aisler/32/2193_2.png) [@Sarah-from-AISLER](https://community.aisler.net/u/Sarah-from-AISLER)\
**Post date:** [September 21, 2026, 11:12am UTC](https://community.aisler.net/t/stencil-size-specifiation-outdated/5899/2 "2026-09-21T11:12:57Z")

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Hi @Joel1,

you’re right - the top margin in the spec was outdated: the correct value is ≥ 20mm, an we’ve updated the [Prototype Stencil Specification](https://community.aisler.net/t/prototype-stencil-specification/3412) accordingly.

There’s no exact rule that would let you predict the exact top edge, I’m afraid. Due to the way we manufacture the stencils, the top margin varies from order to order, so we can only guarantee the minimum. Your 22.72 mm is within spec.

Thanks for measuring this so thoroughly, it’s how we caught the outdated value. 🧡

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**Author:** ![system](https://community-cdn.aisler.net/user_avatar/community.aisler.net/system/32/28_2.png) [@system](https://community.aisler.net/u/system)\
**Post date:** [September 22, 2026, 7:13am UTC](https://community.aisler.net/t/stencil-size-specifiation-outdated/5899/3 "2026-09-22T07:13:58Z")

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