If the deckle belongs to a laid mould small grooves are filed into the rim where the chain wires stick up.
Placing the deckle on the mould and rubbing it around will cause the chain wires to leave visible dents in the wood. The deckle is turned 180 degrees and rubbed on the mould that way, too. (Or both ways on two moulds if it belongs to a ‘production style’ pair of two moulds and one deckle). If the chain wires were carefully aligned when making the mould they will match up both ways (or all four ways for a pair of moulds) and there won’t be a need to file extra grooves.
The dented marks are enlarged just a little at first with a file. Then the deckle is returned to the mould to check the alignment of grooves with chain wires. Some of the marks will be hard to see at first; deepening the ones that show first will allow the others to show up.
A ‘slim’ or ‘extra slim’ triangular file works well.
The notches should be deep enough that the rim rests on the laid wires to help make a neat edge on the paper.
Shaping the Chamfers
The ends of the chamfers can be carved with a chisel.
The middle parts can be shaped with a spokeshave.
It is traditional to include small chamfers on the short ends of the deckle too. The purpose of these is not clear to me. (This may be important in some way for production use in commercial mills). The short sides have been left flat on top (not chamfered) for the moulds I’ve been making recently. I usually narrow the inner edges of the front and back to about 1/4″. Sometimes the deckles are left full depth on all four sides (with no chamfers at all) if thick paper is to be made. Over the years I’ve offered to make the inner deckle rims to any dimension but have received little feedback. 1/4″ seems to work well for most contemporary sheet forming methods.
This single facet chamfer would probably work fine but I broaden the chamfer up over the top surface in a gentle curve.
A cabinet scraper can be used as part of this process.
Sandpaper finishes the job.
The outside curves are also sanded.
The entire deckle is sanded with the exception of the four inside (vertical) edges which retain their original ‘jointed’ surfaces. Along their bottom edges (where they meet the deckle rim) the corners are left fairly sharp and eased only slightly with very fine abrasive paper. (320 or 400 wet/dry over a small block works well).
When the shaping is done I soak the deckle thoroughly to raise the grain as shown here. After it dries I give it a once-over with a fine sanding sponge before applying any finish. As with the wooden parts of the mould the finish can be boiled linseed oil, tung oil or Watco oil. The finish won’t last very long (and that’s OK). The deckle and mould are ready to use!