Plenty of good booths change hands with no manual, a painted-over nameplate, or a badge from a company that no longer exists. If you cannot look up a part number, you can still get the right filters — you just size them from the booth itself. This guide gives you a practical method to measure paint booth filter openings on an unknown or rebadged booth, match the correct media type to each stage, and handle the odd sizes that stock filters were never made for.
Start with the booth, not the badge
When there is no reliable model number, the openings are your source of truth. A paint booth filters into three possible stages, and you measure each the same disciplined way: measure the opening the media has to cover, in inches, width by height (or width by length for ceilings). Do not measure the old filter that happens to be in there — it may be the wrong size already, or trimmed. Measure the frame or grid opening the media is meant to fill. Our guide to measuring for the right filter size covers the technique in detail; below is how to apply it stage by stage on a mystery booth.
Stage 1: Ceiling intake grids
In a downdraft or semi-downdraft booth, the ceiling holds intake media in a grid of openings. Measure a single grid opening — width and length of the actual filtered area — and count how many openings the ceiling has. If the openings are all the same size, you have your repeat dimension and your quantity. Ceiling media is typically a tackified polyester or synthetic blanket (commonly F5/M5 ceiling class) that holds incoming dust without shedding onto your finish. If you want to understand why downdraft, crossflow, and semi-downdraft booths lay their stages out differently, our breakdown of downdraft, crossflow, and semi-downdraft filter setups shows where each stage sits. Stock options live in our ceiling blanket filters collection.
Stage 2: Exhaust frames
At the back or floor of the booth, the exhaust frames hold your overspray filter. Measure the frame opening — width by height — and note the holder style (slide-in track, clip frame, or bag header). Note how many frames there are. Test data for each filter in our paint booth exhaust filters collection is on its product page.
Stage 3: Prefilter / intake panel frames
Many booths have a prefilter or intake panel stage — a bank of frames feeding the air makeup or the fan intake. Measure each frame opening and note the media depth the frame accepts (1" and 2" are common). Match a panel or pad media of the same nominal size and depth. Matching depth matters as much as face size — a 2" frame needs 2" media to seat and seal correctly.
Match the media type to each stage
Size is only half the answer — each stage needs the correct type of media, and mixing them up wrecks either your finish or your overspray capture:
| Stage | Job | Typical media |
|---|---|---|
| Ceiling intake | Keep incoming dirt off the finish | Tackified ceiling blanket (F5/M5 class) |
| Prefilter / intake panel | Protect fan / air makeup, first dust catch | Panel or pad media, matched depth |
| Exhaust | Capture overspray | Rated exhaust media |
If you are unsure which stage you are even looking at, our explainer on the difference between intake and exhaust filters makes the roles clear so you do not put the wrong media in the wrong frame.
When nothing standard fits: go custom-cut
Rebadged and shop-built booths frequently use openings that do not match any standard filter size — that is the whole reason the paperwork trail went cold. Rather than force an overlap or trim a stock piece down (and pay for media you throw away), order the exact size. Our Custom Cut ceiling filter blanket is made to your precise width and length — any size, any booth — so an odd grid gets a clean, seamless piece. The full ordering process is in how to order custom-cut filters for any size booth, and our companion piece on custom-cut vs. pre-sized blankets shows when custom actually costs less than stock.
Cross-check against known models
Once you have your measurements, it is worth trying to identify the booth anyway — dimensions plus a few clues (downdraft vs. crossflow, number of ceiling openings, fan location) often point to a family even when the badge is gone. Our guide on how to find your paint booth filter part number walks through the detective work of matching a booth to a known configuration, and our filter size chart by brand lists the common opening sizes for major booth makers so you can sanity-check what you measured. Even if you cannot pin the exact model, your measured openings are all you actually need to order.
Frequently asked questions
How do I measure filters if I don't know my booth model?
Measure the openings directly. For ceilings, measure a single grid opening (width x length) and count the openings. For exhaust and prefilter stages, measure each frame opening (width x height) and note the media depth the frame accepts. The openings, not the model number, tell you what to order.
Should I measure the old filter or the frame?
The frame or grid opening. The old filter may already be the wrong size or trimmed down, so it is not a reliable reference. Measure the space the media is meant to fill.
What if my booth uses a non-standard size?
Order custom-cut media made to your exact dimensions. Rebadged and shop-built booths often use openings that no standard filter matches, and custom-cut gives you a clean, seamless fit with no trimming or overlap.
Can I put any filter in the exhaust frames as long as it fits?
No. Match the size to your frame, but only use media rated for exhaust overspray capture, and check its test data.
Send us your measurements
Give us your ceiling grid, exhaust frame, and prefilter openings and we will spec the full filter set — correct type, correct size, rated exhaust media with test data — and cut anything custom that needs it. Start with Find My Filter, or browse the exhaust and ceiling collections and we will confirm the fit before you order.
Send us your measurements, get the exact filters
Ceiling, exhaust, and prefilter — we can spec all three from your openings alone, no booth ID needed. Orders placed before 2pm MST ship the same day.
Shop exhaust filters →
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