Calibrating pH papers - sanity check?

Not exactly sure if the title is entirely accurate but basically my problem is that the colour chart for two different sets of pH papers are useless. The colours for more than a couple of values are near identical but none of the colours appear to match with reality anyway! So I need a way to make my own colour chart using the papers I have. For now I'm just interested in measuring alkalinity. The "colour chart" was made by making up solutions for the pH integer values 8-14 and then dipping some pH paper in it and taking a photo of the whole set of values.

I'd like my working out to be sanity checked. Here goes:

I made up a 1.0 M solution of NaOH which by definition is pH 14. The next solution of pH 13 was made by taking a 5 mL aliquot of the former solution and diluting it to 50 mL by adding 45 mL of water. The concentration in this new solution has now been shifted by an order of magnitude, which accords with the pH scale.

The next solution of pH 12 was made in the same fashion: a 5 mL aliquot of pH 13 solution was diluted to 50 mL by adding 45 mL of water.

And so on and so forth until I had the whole set of pH values down to 8.

In the photos the ph 6-13 papers are the long strips, and the pH papers that measure 1-14 are the squares (above).

Quote: Originally posted by VincenzoTheGreat

I'd like my working out to be sanity checked. Here goes: I made up a 1.0 M solution of NaOH which by definition is pH 14. The next solution of pH 13 was made by taking a 5 mL aliquot of the former solution and diluting it to 50 mL by adding 45 mL of water. The concentration in this new solution has now been shifted by an order of magnitude, which accords with the pH scale. The next solution of pH 12 was made in the same fashion: a 5 mL aliquot of pH 13 solution was diluted to 50 mL by adding 45 mL of water. And so on and so forth until I had the whole set of pH values down to 8.

The papers were bought new but who knows how old they are. Two separate brands: Hydrion and Thermo Fischer.

I thought of buying a pen-type pH tester then remembered I have a $500 professional grade electronic meter with calibration standards. smh. Oh, and a pen-type pH meter (the pool/hydroponic type). That's what I get for having too much chemistry gear I suppose

@DraconicAcid I agree, NaOH isn't ideal but the stuff I was using was pretty fresh, and even accounting for moisture in the air and decomposition products I think it's fine in this instance given the margin of error (a whole pH unit). You can see in the pictures at the upper end of the scale there are definite changes in the paper colour then virtually none at all.

My money is on the papers being shite.

Can anyone recommend a brand they've had consistent results with? And whose colour chart doesn't suck?