4 mil mountboard


SPFG, Supreme Picture Framing God
Oct 26, 2004
Wayzata, Minnesota
We mount almost everything on 3/16 foamboard.

I have some 22 x 28 inkjet prints that need to be mounted on 4-mil board. The slip in frame doesn’t allow for anything thicker.

Any reason I shouldn’t use any old matboard.

No preservation issues here. The prints are used for point of sale advertising.

Is "4 mil" 4mm??? (reason I ask is that Matboard is 1.5mm)

There is no reason not to mount to old Matboard for POS materials IMHO. We do it all the time, although if it runs out we'll use fluteboard instead.
The problem with .055" board (standard mat board) is that it is not stiff enough to support a 22x28. your 4mm board (.154") is thicker that 1/8". Why not use 1/8" foam centered board?

What in the world do you have (4mm board)? The old triple thick chip board mount boards?
If I understand your question correctly and my arithmetic skills are not failing me, “4 mil” is, I believe, 0.04 inches which roughly translates into a little over 1/32”.

Again, if I’m correct on that assumption, 1/32” is, I believe, way too thin to support a print of that size without bowing in the frame.
For the confused - prepare to be more so!

I think DVieau2 means 4-ply board, ie, standard matboard...

mils have nothing whatever to do with millimetres (mm), except the Latin derivation of the name (where deci means a tenth of, centi means one hundredth, milli one thousandth and micro equals one millionth).

A mil is a milli-inch ~ one thousandth of an inch, or if you prefer 1/1000th". I don't know of any symbol for it but to add to the confusion, some call it a micro-inch! (A bit like billions I suppose - the Imperial system holds that a billion is a million million, but the whole world now follows the American standard of a thousand million... now anyone can be a billionaire - under the old British system, there still wouldn't be any!) Back to the chase...

The equivalent Metric System mini-measure is microns or micrometres, or if you're American, I guess that's micrometers... but nobody ever accused the Yanks of knowing much about English! Ouch!

The symbol for micron is µm and one µm equals 1/millionth of a metre (m), or 1/1000th of a millimetre (mm), or 1/10000th of a centimetre (cm), or 1/25400th of an inch - ie, approx 1/25th of a mil - or if you prefer - 1mm = just on 40mil (ie 40 thousandths of an inch).

And for good measure - an inch is 25.4mm and a yard is 915mm. A metre is 3.2808 feet. There's 1000m in a kilometre (km) and there's about 1.6km to the mile. Enough already!

So, apart from showing that the US should stop being the last hold-out and get with the program in going metric asap, where does that leave us?

Well, standard 4-ply matboard is indeed about 1.5mm or 60mil thick. Jfeig's 0.055" is right on the button.

But sorry Bill - back to school! - 4mil (or "4 thou." if you're Australian) is 4/1000ths of an inch, or 0.004 inch, or 1/250th", but 1/32" is just over 31 thou. - 31.25mil to be precise... so 1/32" and 32 thou. are very different animals.

And after all that, I think I need a sleep!

4 ply board is approx. .055".

As I said before it is too flimsy for a 22 x 28

What is a "slip" ? If you are referring to the rabbitt, most are at least 1/4" and should be able to handle foam core. What type of frame are you suggesting? Is there more to the frame package that you did not tell us (mats)?

Just in case that the frame is the only one that the client likes, there is always rabbit space.

[ 12-13-2004, 03:23 PM: Message edited by: JFeig ]

She may be referring to a "slip-in" frame, maybe a top loader or something similar. Some of them are shallow and you don't have alot of choice in using what will slide into the frame.

Thanks Rod... I think... I won’t make that mistake again.

Jerome... the frame is made by a store fixture manufacturer and is top loading.

Framerguy... I’m a he not a she!

I think I’ll mount them on regular mat board.

The symbol for micron is µm and one µm equals 1/millionth of a metre (m), or 1/1000th of a millimetre (mm), or 1/10000th of a centimetre (cm), or 1/25400th of an inch - ie, approx 1/25th of a mil - or if you prefer - 1mm = just on 40mil (ie 40 thousandths of an inch).
Okay, who’s the wise guy who let Rod in here? It’s a well know fact that picture framers are lousy at measuring stuff. “That looks about right” is all the arithmetic that any of us need. When trying to convert 4 mils to the real world using the generally accepted equation, 5/9 (C° * sqr (–1) ), we end up 6.025 x 10<sup>23</sup> furlongs/light year which, as all of us know, “looks about right”, and it good enough for most of us.

Of course, Legends213 has a distinct advantage ‘cause he’s from the Land of Oz, where, because he’s upside down, all the blood surges to his head and makes him smarter.

In the northern hemisphere all the blood rushes to our … um, … sorry, I lost my train of thought.

Welcome to the Grumble, Rod.
"I see, says the blind man"

I am more than familiar with those "Sign Frames" having worked for more than 12 years for a couple of Fortune 500 retailers.

Yes, standard board (x board, 40c chip board, etc ) is your only choice for mounting. The norm is that warping is not a defect.
Thanks Bill...

I think in the northern hemisphere, all the blood rushes to your ingenuity!

Which reminds me of the Irish carpenter who, when the Englishman declared the Irishman's measurement perfect, said - "that'll be near enough then."

A wonderful science which still can't divide a tricycle between three small boys.
(Earl Wilson)
People who feel rich because they charge each other so much. (anon)
People too drunk to feel their sunburn. (anon)