Chill cucumbers overnight in fridge, or, let soak in a tub or sink of ice water for several hours.
Trim both ends off the cucumbers, then halve or quarter them lengthwise. Set aside in a large bowl.
Put the vinegar, water and pickling spice (in a spice bag) in a pot. Add salt (or salt sub) and sugar, (or liquid stevia.)
Bring to a boil, then simmer covered for 15 minutes.
In each half-litre (US pint) jar put: 1 bay leaf, 1 peeled clove garlic, 1 teaspoon dill seed, 1 teaspoon mustard seed, ¼ teaspoon red pepper flakes per jar, ⅛th teaspoon pickle crisp. (Double all these measurements for litre / US quart jars.)
Pack raw cucumber halves or quarters upright into the jars. Leave 2 cm (½ inch) headspace.
Fill each jar with the vinegar mixture up to 2 cm (½ inch) from the top.
If you are short of the vinegar mixture, top up the jars with either pure vinegar or a mixture of half vinegar / half water (do NOT use all water.) Bring your top up liquid to a quick boil in the microwave; mind the surge when removing.
Debubble, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jar for 15 minutes; increase time as needed for your altitude.