Hide Cash in Sunglasses Cases (Secret Liner DIY)
A discreet cash pocket can be made as a removable fabric liner for a sunglasses case. Measure the case first, keep the pocket flat, and leave moving parts clear. The insert must not press on glasses or force the case shut. These measurements are cautious DIY targets, not safety standards; test the finished liner with the case’s intended contents.
Before adding a liner, a case may look like ordinary eyewear storage but have no safe place for folded cash. Afterward, a slim removable pocket can hold a small amount without changing the case itself. The key is to protect the glasses first: a case that closes can still press cash or a pocket against the lenses.
I approach this as a small sewing project, not a security device. It may suit lawful personal storage, but it does not make cash theft-proof. Keep the amount modest, and do not use this method to conceal items from someone who has a legal right to inspect them.
Plan the Liner and Measure the Case
A liner is a removable layer that sits against one flat interior panel. It should not cover the hinge, clasp, or areas that support the glasses. Measure the actual case rather than relying on a standard size, since shapes and interior layouts vary.
Survey the interior
Open the case and remove its contents. Check that the inside is clean and dry, then note the flat area where a liner could sit. Look for the hinge, clasp, nose bridge, and any raised or padded sections that may reduce usable space.
Use a ruler or flexible measuring tape to record the panel’s usable width and length. Leave at least 3 mm of clearance at each side and end when sizing the liner. Treat this as a conservative DIY target, not a manufacturer rule.
Also measure the available depth when the case is closed. The liner, pocket, cash, and any backing must fit together without pressure. Aim for at least 2 mm of spare depth after the case closes freely.
Make a paper pattern
Cut a paper shape slightly smaller than the flat panel, using your measurements and clearances. Place it inside the case and check that it does not overlap the hinge, clasp, or areas where the glasses rest. Close the empty case gently, then open it and inspect whether the pattern shifted.
Do not assume the case is safe just because the paper fits. Paper is thinner than fabric and cash, so the pattern only checks the outline. Keep this template for the next stage, and adjust it if any edge reaches a moving part.
Check Hinge, Clasp, and Contents Clearances
Clearance means open space between the liner and a part that moves or must fit without pressure. Keep the insert at least 5 mm away from hinges, clasps, and other moving parts. Then test it with the glasses you plan to store, because the frame and lenses may sit differently from an empty case.
Find pressure points before sewing
Place the paper pattern in the case and add the glasses. Check that the frame rests as it normally would and that the paper does not bunch beneath it. If a nose bridge or lens touches the proposed pocket area, choose another panel or skip the modification.
Next, consider where folded cash would sit. A folded bill adds thickness, and several bills can form a firm edge. Do not place that edge beneath a lens, frame, or nose bridge. The pocket should lie on a flat panel, away from the eyewear’s contact points.
Treat closure as a test, not proof
Close the case gently with the glasses inside and notice any extra resistance. The clasp should engage as it does normally, without pushing, squeezing, or holding the lid down. Reopen it and look for a shifted frame, marks, or signs that the liner has moved.
A case that closes is not automatically safe for glasses. Pressure can pass through a soft liner and affect the contents even when the clasp catches. If you feel resistance or see a change in how the glasses sit, remove the insert or redesign it.
Choose Materials for a Removable Pocket
Use thin, soft fabric for the pocket so it can hold cash without creating a bulky seam. A suitable target is 0.8–1.5 mm fabric, measured as a practical selection range rather than a required specification. Skip stiff trims, thick layers, and rough edges that could catch on glasses or the case lining.
Fabric and optional backing
A smooth woven fabric is a practical choice because it can be cut and sewn into a flat pocket. Check the fabric’s care and use instructions, especially if it has a coating or finish. Avoid loose fibers, sharp fasteners, and parts that could come free inside the case.
If the panel needs a little structure, use 1–2 mm closed-cell EVA foam only as a removable backing or padding. Closed-cell foam has a compact structure and is often used as a thin cushioning material, but the exact product can vary. Keep it separate from the glasses and confirm the added thickness still leaves room to close.
| Option | Useful when | Main trade-off |
|---|---|---|
| Thin fabric pocket, no backing | The case has a flat panel and enough support | May wrinkle if cut too large |
| Fabric pocket with removable EVA backing | A thin panel needs light support | Adds thickness that must be tested |
| Thick padding or rigid insert | Not recommended for this project | Can press on glasses or strain the clasp |
Do not use solvent-based adhesive or make a permanent change unless the case maker confirms the material is compatible. Adhesives may affect finishes or linings, and a permanent attachment is harder to remove if it interferes with closure. A sewn pocket or removable sleeve gives you a way to revise the fit.
Make a Removable, Low-Profile Pocket
A low-profile pocket is a flat pouch that holds a small amount of cash without creating a raised lump. Build it for the case’s measured panel, not for a presumed universal shape. Keep seams narrow and edges smooth, and make the insert easy to remove for cleaning or inspection.
Sew the pocket
Use the paper template to cut a fabric liner that stays within the measured clearances. Cut a separate pocket piece that is only large enough for the folded cash you intend to carry. Position it on the liner’s flat panel, away from the hinge, clasp, and eyewear contact points.
Sew the pocket to the liner with a flat seam. Avoid bulky folded hems where possible; trim loose threads and check that no sharp or stiff parts remain. The pocket should not be overfilled. If the cash makes a lump, reduce the amount or use a different storage method.
Make a removable sleeve
If sewing a pocket directly to the liner is not practical, make a fabric sleeve that fits over a thin EVA backing. The sleeve should stay in place without clips or hard fasteners, and the backing must remain removable. Keep the finished insert thin enough to meet the case’s clearance and closure checks.
Do not attach the insert to the hinge or clasp, and do not force it into a narrow space. If it slips, bunches, or blocks the case from opening normally, revise the size rather than adding a rigid part. The finished liner should come out without tools.
Verify Closure and Protect the Eyewear
Verification is a repeat check of fit, movement, and pressure after the liner is made. Test the empty case first, then test it with the liner and intended contents. Remove the insert at once if the clasp works differently, the glasses shift, or anything snags.
Run a step-by-step fit test
- Put the liner in place and confirm it stays on the flat panel.
- Check that it remains at least 5 mm clear of hinges, clasps, and moving parts.
- Add the intended cash, folded as it will be carried.
- Place the glasses in their normal position. Do not store them against a protruding pocket or folded cash.
- Close and reopen the case several times, using light pressure only.
- Check for pressure marks, snagging, loose pieces, shifted glasses, or a clasp that feels different.
- Confirm at least 2 mm of spare depth remains when the case is closed.
These numbers are conservative targets for this DIY project, not limits set by building codes or a universal eyewear standard. The case maker’s instructions and the actual fit take priority. If you cannot confirm comfortable closure and safe spacing with the glasses inside, do not use the liner in that case.
Example Fit Checks for Different Cases
These scenarios are examples of how to apply the measurement steps, not reports of tested products. A case’s shape and the glasses it holds matter more than its label. Use the measurements below as decision points, then verify the fit in your own case.
Flat-panel case
Imagine a case with one broad, flat inner panel and a hinge at the rear. A paper template shows room for a small liner, with 3 mm clear at the sides and ends and 5 mm clear of the hinge and clasp. The pocket can be sewn onto the panel, provided it does not sit under the glasses.
The next check is depth. Add the folded cash and glasses, close the lid without force, and confirm the clasp feels normal. If the cash creates a raised spot, reduce the load or abandon the insert.
Narrow or molded case
A case with curved walls, deep shaping, or a tight fit may not have a safe flat panel. A paper pattern might fit the outline but overlap a nose bridge or frame support. In that situation, the best result may be no liner at all.
Do not try to make a rigid insert fit a narrow case, and do not rely on an overfilled pocket to stay in place. Protecting the eyewear matters more than adding a hidden storage spot.
Common Mistakes to Avoid
Most problems come from adding more material than the case can hold or placing a pocket where the glasses rest. A neat-looking insert can still create pressure. Keep the design simple, removable, and easy to inspect.
- Using the case’s outside dimensions: Measure only the usable interior panel.
- Skipping the contents test: Cash and frames change the fit; test them together.
- Adding thick seams or too much cash: A raised edge can press on lenses or frames.
- Blocking moving parts: Keep the stated clearances and check the opening action.
- Forcing the clasp: A clasp that needs extra pressure is a warning, not a successful fit.
- Using permanent adhesive without approval: The case material may not tolerate it.
- Treating the case as secure storage: It is an ordinary portable case, not a safe.
Conclusion
A removable fabric pocket can be a simple way to carry a small amount of personal cash, but only if the case still protects its eyewear. Measure the flat panel, leave space around moving parts, and use thin materials. Test with the actual glasses and folded cash, and remove the insert if closure or fit changes.
FAQ
Can I put folded cash in any sunglasses case?
No. Use a case only if it has a flat area and enough room to close freely with both cash and glasses inside.
What fabric thickness should I use?
A conservative target is 0.8–1.5 mm. Choose smooth fabric and avoid bulky seams or stiff trim.
How much clearance should the liner have?
Leave at least 3 mm at each side and end, and at least 5 mm from hinges, clasps, and moving parts. Check the actual case.
Can I use foam behind the liner?
You can use 1–2 mm closed-cell EVA foam as removable backing or padding. Test the added thickness with the glasses in place.
How much extra depth should remain?
Aim for at least 2 mm of spare depth when the case is closed. The case should close without extra force.
Is a case safe if the clasp still shuts?
Not always. The liner or cash may still press on the lenses or frame, so check the contents after closing and reopening.
Should I glue the pocket inside the case?
Avoid permanent or solvent-based adhesive unless the case manufacturer confirms it is compatible. A removable sewn liner is easier to adjust.
How much cash should the pocket hold?
Only carry an amount that lies flat without making a lump. There is no universal safe amount; it depends on the case and the fold.
What if the liner shifts or catches?
Remove it and revise the pattern. Do not add a hard fastener or force the insert against the hinge or clasp.
Does this make cash theft-proof?
No. A sunglasses case is not secure storage. Treat the pocket as a discreet carrying option, not protection against theft.
(This article was written by one of our staff writers, Ethan Caldwell. Visit our Meet the Team page.)
