Steel shims for permanent slides

[SuiGenerisBrewing]

I recently received a prepared slide (containing a cross-section of a stone pine needle) that we are using as a standard while trialing some new scopes and analysis software. The slide is prepared in an interesting way - a thin steel ring was glued to a slide to create a well into which the sample was placed, the well filled with a high-optical density mounting medium, and then a coverglass glued on top creating a sealed chamber with the sample inside. I was thinking that similar slides would be easy to prepare at home, using narrow (0.1-0.5 mm) steel shims, which are readily available in machine shops. I measured the ring used on the slide, and its 17mm ID/24mm OD, which is a common size for steel shims, and would nicely work with 25mm circular coverslips.

Clearly this company is using shims (or something very similar) to make their slides, and I think it would work well for making some types of permanent mounts. I couldn't find any protocols for this (e.g. glues and mounting mediums to use, etc), but I'm certain there is a way to do it. Does anyone have a protocol for something similar that they'd care to share?

An image of the stone pine, just to show off how pretty it is:

PineNeedle.jpg (39.85 KiB) Viewed 1669 times

[Hobbyst46]

An important topic IMHO. I was interested in the same for mounting thick diatoms, to preserve their 3D structure. I bought 0.1mm and 0.2mm thick shim rings, OD ~ 18mm.
The glue adds thickness. Moreover, the glue which is used to initially attach the coverslip to the slide must withstand the conditions (e.g. heat) of later mounting in resin within the well created by the metallic ring.
When my specimen was mounted dry, in air, I simply glued the ring to the slide with gel nail polish, which is cured under UV. I think that the final thickness of the NP layer was 0.05-0.1mm.
The coverslip was then attached to the top surface of the ring with the same NP.

[TonyT]

Using a 'ring' is a standard method, but is usually needed only for thick (often dry) specimens. One UK company sells 18mm diam., 3mm thick aluminum rings for making a 'well-slide'. Specimens less than 1mm thick don't require a 'ring'.
However, 'rings' of almost any depth can be made using a ringing table and a paint, varnish, shellac, or wax to form the 'ring'.

Another, simpler, method is to use Avery reinforcement rings. These are white self-sticking plastic, 0.1 mm thick. They can be colored with permanent markers. One can add as many rings as needed to build a deep well.

Below is a louse mounted in a ringed slide made on a ringing table; and an ant in a well made from 3 layers of Avery rings.

(that seems an exceptionally thick section, most such sections are just a few microns thick, <10 µ, and don't need a well)

louse-paint-ring.jpg (28.64 KiB) Viewed 1598 times

ant-3-rings.jpg (24.12 KiB) Viewed 1598 times